Implement Hydraulic Operations for Parallel Flow Systems{5000, 5051, 5057, 5084} Caterpillar

Agricultural Tractors:

Challenger 35 (PIN: 8DN1-UP; 8RD1-UP; ADK1-UP)

Challenger 45 (PIN: 1DR1-UP; ABF1-UP; 3BK1-UP)

Challenger 55 (PIN: 7DM1-UP; 6NN1-UP; AEN1-UP)

Challenger 65C (PIN: 2ZJ1-1964)

Challenger 65D (PIN: 2ZJ1965-UP)

Challenger 70C (PIN: 2YL1-UP)

Challenger 75C (PIN: 4KK1-UP)

Challenger 75D (PIN: 5AR1-UP)

Challenger 85C (PIN: 9TK1-UP)

Challenger 85D (PIN: 4GR1-UP)

Challenger 65E (PIN: 6GS1-UP)

Challenger 75E (PIN: 6HS1-UP)

Challenger 85E (PIN: 6JS1-UP)

Challenger 95E (PIN: 6KS1-UP)

Introduction

This special instruction provides a description of the operation of the implement hydraulic system for Challenger Agricultural Tractors that are equipped with parallel flow systems.

This special instruction provides the following information:

• A summary of the features of the implement hydraulic system

• A list of optional attachments and hookups that are available

• Guidelines that will help you get optimum performance from the implement hydraulic system for your particular application

Parallel flow for the implement hydraulic system was effective with the following Agricultural Tractors:

• Challenger 35 (PIN: 8DN984; 8RD1; ADK1)

• Challenger 45 (PIN: 1DR2038; ABF1; 3BK1)

• Challenger 55 (PIN: 7DM1495; 6NN1; AEN1)

• All Challenger Tillage Tractors

In this special instruction, "row crop tractor" refers to the following Agricultural Tractors:

• Challenger 35

• Challenger 45

• Challenger 55

In this special instruction, "tillage tractor" refers to the following Agricultural Tractors:

• Challenger 65C

• Challenger 65D

• Challenger 65E

• Challenger 70C

• Challenger 75C

• Challenger 75D

• Challenger 75E

• Challenger 85C

• Challenger 85D

• Challenger 85E

• Challenger 95E

Configurations for Implement Hydraulic Systems

Row Crop Tractors

Earlier Valve Stacks Without Lever Release Couplers

Illustration 1	g00639511
Earlier Implement Valve Stack for Row Crop Tractors (1) No. 1 valve section (2) No. 2 valve section (3) No. 3 valve section (4) Three-point hitch valve (5) Top cover

Note: A fourth implement valve section is available as an attachment.

Later Valve Stacks With Lever Release Couplers

Illustration 2	g00639521
Later Implement Valve Stack for Row Crop Tractors (6) No. 1 valve section (7) No. 2 valve section (8) No. 3 valve section (9) No. 4 valve section (10) Three-point hitch valve (11) Top cover

Note: Male couplers are available from any Caterpillar dealer. A 9X-2017 Coupler is available for a 19 mm (0.75 inch) hose. A 9X-2018 Coupler is available for a 12.7 mm (0.50 inch) hose.

Tillage Tractors

Valve Stack

Illustration 3	g00639531
Implement Valve Stack for Tillage Tractors (12) No. 1 valve section (13) No. 2 valve section (14) No. 3 valve section (15) No. 4 valve section (16) Three-point hitch valve

Note: The valve has been removed from the machine for photographic purposes.

Quick Couplers on C and D Series Tractors

Illustration 4	g00645100
(17) No. 1 valve section (18) No. 2 valve section (19) No. 3 valve section (20) No. 4 valve section

Lever Release Couplers on E Series Tractors

Illustration 5	g00645110
(21) No. 1 valve section (22) No. 2 valve section (23) No. 3 valve section (24) No. 4 valve section

Note: Male couplers are available from any Caterpillar dealer. A 9X-2017 Coupler is available for a 19 mm (0.75 inch) hose. A 9X-2018 Coupler is available for a 12.7 mm (0.50 inch) hose.

Design Changes

Several improvements have been made to the implement hydraulic system. These changes affect the operation of the implement hydraulic system.

Tables 1 and 2 summarize the changes and the tables include the following information:

• Benefits

• Effectivity

• References on retrofitting your machine

Table 1

Design Changes for Row Crop Tractors
Name	Challenger 35	Challenger 45	Challenger 55	Benefits	Able to Retrofit
Improved flow controls (low effort)	8RD76 ADK330	ABF122 3BK370	6NN172 AEN461	Easier to adjust under load	Yes (1)
Improved stability in No. 3 and No. 4 valve sections	8RD76 ADK330	ABF122 3BK370	6NN172 AEN461	Improved performance in certain applications	Yes (1) Only No. 3 valve section and No. 4 valve section
Lever release couplers	8RD76 ADK332	ABF127 3BK377	6NN180 AEN522	You can release the hoses under pressure.	Yes
Larger implement pump	8RD1 ADK1	ABF1 3BK1	6NN1 AEN1	Changed to 163 L/min (43 US gpm) from 121 L/min (32 US gpm)	Yes (2)

( 1 )	Refer to Special Instruction, REHS0456, "Installation of Flow Limiters and Compensator Tubes".
( 2 )	Special Instruction, REHS0453, "Procedure for Field Installation of 43 GPM Implement Pump".

Table 2

Design Changes for the Tillage Tractor
Name	Challenger 65E	Challenger 75E	Challenger 85E	Challenger 95E	Benefits	Able to Retrofit
Lever release couplers	6GS1	6HS1	6JS1	6KS1	You can release the hoses under pressure.	Yes (1)
Implement pump	6GS516	6HS497	6JS534	6KS724	Improved shaft seal	Yes (2)

( 1 )	Refer to Service Magazine, SEPD0482 26 July, "Improved Hydraulic Coupler Retrofit Instructions".
( 2 )	No instructions are available.

Logic for Parallel Flow Systems

The operation of the logic for parallel flow systems is described in the following paragraphs.

All of the valve sections have an equal opportunity to obtain flow. This includes the hitch. The determining factor is the resolved pressure of each of the individual valve sections.

No valve section has absolute priority to flow. If flow demand is greater than the flow that can be supplied by the pump, then the circuits with the lowest pressure will be satisfied first and the circuits that have the highest pressure will be satisfied last.

Power Beyond Connections and Operation

The power beyond circuit is a term that describes a machine's capability to supply an implement with hydraulic power without using the machine's implement valve stack.

Power beyond connections are useful for the following two types of circuits:

• Implements that have flow control valves

• Implements that have multiple circuits that are supplied by a remote mounted valve stack

Note: The remote mounted implement control valves should at least have an on/off valve in order to stop the circuit operation. Also, the remote mounted implement control valves should at least have a flow control valve. The circuit may also have numerous directional valves for different circuit operations.

The power beyond circuits consists of the following components:

• Supply line

• Low pressure return line

• Load sense signal line

If the total requirement for oil is greater than pump supply, then the valve section with the highest pressure requirement will have limited flow.

The power beyond circuit will have limited flow if the following two conditions are met:

• The pump is not able to supply the oil that is needed for the power beyond circuit and the implement valve.

• The power beyond circuit has the highest pressure.

The load sense signal line should extend from the shuttle valve on the machine to the remotely mounted valves.

The load sense signal line can be connected to the implement system in the following three ways:

1. Connect the load sense signal line into the implement circuit after the flow control valve by using a tee. This is the best connection because the pump is required only to maintain the margin pressure across the remote flow control valve.

   Note: Make sure that you do not use any undersized lines or couplers if you use this method. This could result in insufficient margin pressure.

2. Connect the load sense signal line into the port that is on the remote valve. This is the remote valve that sends a signal from the load sense circuit to the pump.

   If the remote valve does not purge the signal from the load sense circuit internally, a purge orifice and a line may be needed in order to purge trapped oil. This will also prevent the pump from staying at maximum system pressure.

3. The load sense signal line should be connected by a tee into the load sense signal line that is on the implement.

   Connect the load sense signal line in this way if the circuit tends to bleed off. This connection should be made before the flow control and the on/off valve.

   This type of connection is the most inefficient connection. This connection will send the hydraulic system to maximum system pressure.

Several different quick couplers are available to be used in power beyond circuits on Challenger Agricultural Tractors. Because the quick couplers are larger, the couplers will have a lower pressure drop than the couplers that are on the machine. The couplers also provide various features.

The correct choice for a quick coupler is important. This choice will depend on the application.

Reference: See ""Power Beyond Connection for Row Crop Tractors" " for more details.

Power Beyond Connection for Row Crop Tractors

Table 3 and Illustration 6 describe a complete power beyond system on the row crop tractor. This system does not use standard quick couplers for the implements.

When you use the power beyond connection for the supply line, the implement must have a signal line or a load sense signal line. The load sense signal line must be connected to the resolver network. This can be done by connecting coupler (33) to the load sense signal line for the implement.

Remote valve (31) has an internal bleed orifice so one is not needed on the implement.

The current design for the power beyond system contains an internal resolver. The current design also has connections for the load sense signal lines and the supply lines. The connections are in the end cover.

See Table 3 and Illustration 6 for the correct parts.

Note: The remote valve assembly (end cover) is different if the machine is equipped with a three-point hitch.

Table 3

Required Parts
Item	Part Number	Description	Qty
25	4E-5124	Cap Assembly	1
26	190-1479	Adapter	1
27	122-1802	Coupler	1
28	153-4061	Fitting	1
29	153-6225	Dust Cap	1
30	153-6229	Elbow	1
31	153-6533 (1) or 153-2183 (2)	Remote Valve	1
32	159-5893	Dust Cap	1
33	159-5897	Coupler	1
34	159-5898	Fitting	1
35	159-6071	Dust Cap	1
36	2M-9780	O-Ring Seal	1
37	3J-1907	O-Ring Seal	2
38	3J-7354	O-Ring Seal	1
39	7J-9108	O-Ring Seal	1
40	7M-8485	O-Ring Seal	1

( 1 )	Use this valve on machines that are not equipped with a three-point hitch.
( 2 )	Use this valve on machines that are equipped with a three-point hitch.

Illustration 6	g00639706
(A) Implement Valve

Power Beyond Connections for Tillage Tractors

Tillage tractors provide hookups for power beyond supply through the use of power beyond tees that are installed in the end cover for the implement valve.

Note: Not all earlier machines were equipped with power beyond tees at the factory.

Reference: Refer to Service Magazine, SEPD0213 27 June, "Power Beyond For Challenger Agricultural Tractors" for more information.

Since the implement valve does not have a port in the end cover for the load sense signal line, a signal line from the implement must be connected to the signal line on the machine. When you use a power beyond connection for the supply line, the implement must have a signal line or a load sense signal line.

The implement should have a shuttle valve in order to correctly resolve signals from the power beyond system and the machine's implement valve. This will allow the implement to correctly function.

The shuttle valve should also have an internal drain in order to bleed off signal pressure when no demand is seen in the circuit. If an internal drain is not available and a ball resolver is used, the pump may not destroke in a timely manner. The pump may remain at maximum system pressure until leakage bleeds off signal pressure.

Adapters are available to fit the more common hose fittings on implements. See callout (77) and callout (78) in Illustration 13. Be aware that most implements are equipped with hoses that are too small in diameter for the flow requirements.

You may frequently observe a 12.7 mm (0.50 inch) or smaller hose that is being used in lift circuits or motor circuits. These circuits should have hose with a minimum inside diameter of 19.0 mm (0.75 inch).

Hoses that are too small can cause the following problems:

• Excessive restriction which causes a pressure drop in the system

• Increased resolved pressures

• Insufficient flow and pressure to the motor or cylinder

In order to minimize any restriction in the system, do not adapt inadequate hoses to the fittings that are shown in Table 8. Install hoses that better meet the needs of the implement and match the size of the quick couplers.

Implement Load Sense Signal Line

The load sense signal line for the implement must be connected to the load sense signal line of the tractor's valve by use of a shuttle valve.

Tillage Tractors That Are Not Equipped with a Three-Point Hitch

Table 4, Table 5, Illustrations 7, Illustration 8, and Illustration 9 are for the following Agricultural Tractors:

• Challenger 65C (PIN: 2ZJ1-1964)

• Challenger 65D (PIN: 2ZJ1965-UP)

• Challenger 65E (PIN: 6GS1-UP)

• Challenger 70C (PIN: 2YL1-UP)

• Challenger 75C (PIN: 4KK1-UP)

• Challenger 75D (PIN: 5AR1-UP)

• Challenger 75E (PIN: 6HS1-UP)

• Challenger 85C (PIN: 9TK1-UP)

• Challenger 85D (PIN: 4GR1-UP)

• Challenger 85E (PIN: 6JS1-UP)

• Challenger 95E (PIN: 6KS1-UP)

Reference: If the implement is equipped with a shuttle valve, see Table 4 and Illustration 7. If there is no shuttle valve on the implement, see Table 5, Illustration 8, and Illustration 9.

Table 4

Required Parts for Illustration 7
Item	Part Number	Description	Qty
41	3J-1907	O-Ring Seal	2
42	6V-8730	Face Seal Union	1

Illustration 7	g00745898
Implement Shuttle Valve (B) Hose from implement (Resolved signal) (C) Shuttle valve on implement (D) Elbow for signal line

Table 5

Required Parts for Illustrations 8 and 9
Item	Part Number	Description	Qty
43	159-5897	Coupler	1
44	6V-8636	Connector	3
45	3J-1907	O-Ring Seal	4
46	6V-9961	Coupling	2
47	6V-8397	O-Ring Seal	4
48	8T-0788	Elbow	1
49	8J-6875	Shuttle Valve Assembly	1
50	6V-8724	Elbow	1
51	2P-5943	Hose (1)

( 1 )

Cut to required length.

Illustration 8	g00742291
Right Side View (Shuttle valve on tractor)

Note: Use Items (28), (29), (32), and (37) in order to connect the load sense signal line to coupler (43).

Illustration 9	g00651606
Top View (Shuttle valve on tractor) (E) End cover

Tillage Tractors That Are Equipped with a Three-Point Hitch

Tables 6 and 7 and Illustrations 10, 11, and 12 are for the following Agricultural Tractors:

• Challenger 65C (PIN: 2ZJ1-1964)

• Challenger 65D (PIN: 2ZJ1965-UP)

• Challenger 65E (PIN: 6GS1-UP)

• Challenger 70C (PIN: 2YL1-UP)

• Challenger 75C (PIN: 4KK1-UP)

• Challenger 75D (PIN: 5AR1-UP)

• Challenger 75E (PIN: 6HS1-UP)

• Challenger 85C (PIN: 9TK1-UP)

• Challenger 85D (PIN: 4GR1-UP)

• Challenger 85E (PIN: 6JS1-UP)

• Challenger 95E (PIN: 6KS1-UP)

Reference: If the implement is equipped with a shuttle valve, see Illustration 10. If the implement is not equipped with a shuttle valve, see Illustrations 11 and 12.

Table 6

Required Parts for Illustration 10
Item	Part Number	Description	Qty
52	3J-1907	O-Ring Seal	2
53	6V-8730	Face Seal Union	1

Illustration 10	g00745900
Shuttle Valve on Implement (Top View) (F) Hoses from implement (G) Shuttle valve

Note: The shuttle valve is mounted on the implement.

Table 7

Required Parts for Illustrations 11 and 12
Item	Part Number	Description	Qty
54	6V-8398	O-Ring Seal	2
55	3J-1907	O-Ring Seal	4
56	6V-9873	Connector	1
57	6V-8397	O-Ring Seal	4
58	6V-8076	Elbow	1
59	9X-2847	Swivel Adapter	1
60	6V-8724	Elbow	1
61	6R-7605	Shuttle Valve	1

Illustration 11	g00639692
Shuttle Valve on Tractor (Top View)

Illustration 12	g00653405
Shuttle Valve on Tractor (Right Side View) (H) Existing tube assembly

Implement System Return Line for the Power Beyond Circuit

All Machines

A low pressure return port is used to return the normal working flows back to the tank. Oil flow in return lines can be high and depending on the application and restrictions (return filter and couplers) can also be at moderate pressure.

There are many available fittings that have the following features:

• Wide range of sizes

• Lower pressure drop

• "Breakaway feature"

The coupler will become disconnected from the port automatically if an implement becomes disengaged from the machine. This is referred to as the "breakaway feature".

See Illustration 13 and Table 8 for a complete list of fittings that are available for the low pressure return port. Use the illustration and the table to select the most appropriate combination of couplers and adapters.

Your choice of couplers and adapters will be determined by the following conditions:

• The application

• Required feature

• Existing hose sizes

• Availability of fittings at the dealership

Connecting Supply and Return Lines

The low pressure return ports can be used in other applications in addition to power beyond applications. The port can also be used for the low pressure return oil that comes from an implement valve stack.

The supply oil to the motor (pressure side) should be attached to the retract coupler (-). This connection is especially important for row crop tractors. The connection will allow the oil flow to bypass the restriction that is created by the load check valve. The load check valve is located in the manifold for the quick coupler.

Load check valves are installed on earlier row crop tractors on No. 1 valve section and No. 2 valve section. The supply can also be obtained from the supply port for the power beyond circuit.

Motors that are equipped with internal connections for the motor case drain should use low pressure return connections in order to avoid excess pressure buildup in the motor case. Excessive pressure can reduce the life of the shaft seal.

In addition, the operating pressure of the orbital motor should be checked by running the implement in the work cycle.

High working pressures that are more than 13780 kPa (2000 psi) can be an indication of the following conditions:

• Excessive restriction due to small lines

• An in-line restrictive orifice

• An in-line variable bypass valve on the implement

Note: To correct this situation, the in-line orifice should be removed or the variable bypass should be shut off.

The motor speed should be regulated by adjusting the flow controls on the machine instead of adjusting the speed of the motor on the implement.

You can reduce the buildup of heat in the hydraulic system by providing metered flow from the implement valve that is on the machine.

You can reduce the buildup of heat by eliminating the restriction at the implement. This should be done if the cause for high pressure in the system can not be found or if high pressure in the system is caused by improperly sized motors or cylinders.

Illustration 13	g00742317
Low Pressure Return Connections and Implement Fittings (All Machines)

Table 8

Components for Low Pressure Return Oil
Item	Part Number	Description	Qty
62	7I-8310	Coupling	-
	3D-2824	O-Ring Seal	1
63	5P-2211	Straight Thread Adapter	-
	3D-2824	O-Ring Seal	1
64	5P-9560	Union	-
	3D-2824	O-Ring Seal	2
65	6Y-2349	Connector	-
	3D-2824	O-Ring Seal	2
66	6V-8640	Seal Connector	-
	3D-2824	O-Ring Seal	1
	6V-9746	O-Ring Seal	1
67	160-5558	Adapter	-
	3D-2824	O-Ring Seal	-
68	5R-6304	Coupling (1)	-
	5R-5718	Dust Plug	-
69	151-4799	Coupler (2)	-
	153-6228	Dust Plug	-
70	159-5896	Coupler (3)	-
	168-4599	Dust Cap	-
71	9X-2017	Valved Nipple	-
	3K-0360	O-Ring Seal	1
72	159-5898	Fitting	-
	2M-9780	O-Ring Seal	1
73	9X-2018	Valved Nipple	-
74	5R-6305	Coupling	-
75	159-5890	Fitting	-
	153-6227	Dust Cap	-
76	5P-4481	O-Ring Adapter	-
77	6L-9952	Thread Adapter	-
	3D-2824	O-Ring Seal	-
78	6V-1722	O-Ring Adapter	-
	3D-2824	O-Ring Seal	-
96	6V-8943	Reducer Assembly	-
	6V-9746	O-Ring Seal	1
97	7X-3165	Swivel Adapter	-
	6V-9746	O-Ring Seal	1
J	-	3/4 inch 16 THD	-
K	-	7/8 inch 14 THD	-
L	-	1/2 inch 14 NPTF	-
M	-	3/4 inch No. 8	-
N	-	Low Pressure Return Port (Row Crop)	-
P	-	Low Pressure Return Tee (Tillage)	-

( 1 )	The 3/4 inch coupler will not automatically release if there is an implement breakaway.
( 2 )	The 3/4 inch coupler automatically releases in the event of an implement breakaway. The pressure drop across the coupler is 124 kPa (18 psi) at a flow of 75.7 L/min (20.00 US gpm) when you are using SAE 10W oil at 50 °C (122 °F).
( 3 )	The 1/2 inch coupler automatically releases in the event of an implement breakaway. The pressure drop across the coupler is 640 kPa (93 psi) at a flow of 75.7 L/min (20.00 US gpm) when you are using SAE 10W oil at 50 °C (122 °F).

Drain Lines for Motor Case or Motor Seal

All hydraulic motors have shaft seals. All hydraulic motors also have a case drain. Some motors have drains which connect to the return oil line internally. Other motors have an external motor case drain.

Motor case drain lines have the following characteristics:

• Low flows that are typically less than 8 L/min (2 US gpm)

• Low pressures that are typically less than 690 kPa (100 psi)

• Small hose sizes

• Couplers that have a low pressure drop

The design specifications of the motor determines the characteristics of the motor case drain lines. Motor case pressures must be kept low in order to avoid damage to the shaft seal.

In the instances of variable displacement motors or pumps, high case pressures can result in mechanical damage. For these reasons, connections to the motor case must be designed in order to minimize pressure drop.

Row Crop Tractors

The row crop tractor has a return port to the sump. This port drains directly into the common sump. This port can serve as a low pressure return port or a motor case drain port.

Tillage Tractors

The tillage tractor has a dedicated port for use with motor case drain lines. This port is located on the hydraulic tank. See Illustrations 14 and 15 for the correct location. The low pressure return port can not be used as a motor case drain.

The low pressure return port is located on the end cover that is on the valve stack. (This port will function as a motor case drain on the row crop tractor.)

The oil that flows through the low pressure return connection passes through the implement return oil filter, and a return screen before the oil returns to the tank. This restriction and the oil from the other valve sections make the low pressure return port unacceptable for case drain oil.

Table 9 lists the parts for the following Agricultural Tractors:

• C Series

• D Series

• Early E Series

Reference: See Table 10 for a list of the parts that are needed for later Challenger E Series Agricultural Tractors. Refer to your machine serial number for the correct table.

Also, make sure that you order the correct parts. The parts will vary depending on if the machine is equipped with a valve section for a three-point hitch.

The parts in Table 9 are for the following Agricultural Tractors:

• Challenger 65C

• Challenger 65D

• Challenger 70C

• Challenger 85C

• Challenger 85D

• Challenger 65E (PIN: 6GS1-362)

• Challenger 75E (PIN: 6HS1-339)

• Challenger 85E (PIN: 6JS1-372)

• Challenger 95E (PIN: 6KS1-475)

The parts in Table 10 are for the following Agricultural Tractors:

• Challenger 65E (PIN: 6GS363-UP)

• Challenger 75E (PIN: 6HS340-UP)

• Challenger 85E (PIN: 6JS373-UP)

• Challenger 95E (PIN: 6JS476-UP)

Table 9

Required Parts for C Series, D Series, and Early E-Series Challenger Agricultural Tractors
Item	Part Number	Description	Qty
79	149-2848	Coupling	1
80	124-2114	Orifice Coupling	1
81	124-2116	Permanent Coupling	1
82	122-6869	Hydraulic Hose (1)	-
83	3J-1907	O-Ring Seal	1
84	3K-0360	O-Ring Seal	1
85	4D-7735	Clip	1
86	4D-8309	Retaining Ring	2
87	5P-4295	Clip	1
88	6V-8397	O-Ring Seal	2
89	6V-9001	Elbow (45 degrees)	1
90	161-6289	Bracket (2) (5)	1
91	6V-8625 or 098-5687	Elbow (45 degree) (3) or Tee (4)	1 1
92	166-4872	Bracket (5)	1
93	6V-8398	O-Ring Seal (4)	1
94	149-2847	Quick Coupler Nipple	1
95	153-6223	Dust Plug	1

( 1 )	Order the hose by the inch. 167 cm (66 inch)
( 2 )	Remove the existing 136-4368 Guard .
( 5 )	Remove the existing bracket for the seven pin connector. Relocate the seven pin connector to the 161-6289 Bracket .
( 3 )	This component is for machines that do not have a three-point hitch.
( 4 )	This component is for machines that have a three-point hitch.

Table 10

Required Parts for Later E Series Challenger Agricultural Tractors
Item	Part Number	Description	Qty
79	149-2848	Coupling	1
80	124-2114	Orifice Coupling	1
81	124-2116	Permanent Coupling	1
82	122-6869	Hydraulic Hose (1)	-
83	3J-1907	O-Ring Seal	1
84	3K-0360	O-Ring Seal	1
85	4D-7735	Clip	1
86	4D-8309	Retaining Ring	2
87	5P-4295	Clip	1
88	6V-8397	O-Ring Seal	1
89	6V-9001	Elbow (45 degrees)	1
91	6V-8625 or 098-5687	Elbow (45 degree) (2) or Tee (3)	1 1
92	166-4872	Bracket	1
93	6V-8398	O-Ring Seal	2
94	149-2847	Quick Coupler Nipple	1
95	153-6223	Dust Plug	1

( 1 )	Order the hose by the inch. 167 cm (66 inch)
( 2 )	This component is for machines that do not have a three-point hitch.
( 3 )	This component is for machines that have a three-point hitch.

Illustration 14	g00639981

Illustration 15	g00639986
(Q) Case drain port for the motor

Recommended Connections for Typical Implements

Air Seeder, Seed Drill, and Seed Drill with Chemical Sprayer

Some samples of recommended connections are listed. Use these recommendations as a general guideline. Due to specific requirements by the user, there may be applications that are not included in this instruction.

If your particular application is not listed, follow the general guidelines. Use the information in the previous sections of this publication to determine the best method for connecting your implement to your hydraulic system.

Planters

Planters are very complex implements due to the potential number of circuits from the factory and from aftermarket attachments. There are at least 9 to 10 different circuits that can be found on different planters.

Using Vacuum Motors on Planters

Some blowers on planters run at high speeds and high pressure. The blowers may also have moderate flows to low flows. The implement valve may compensate too much for the fluctuations in the oil pressure. This is because of the extra inertia of the vacuum blower acting against the low flow, high pressure hydraulics. This can cause an instability or "surge" by the blower. You can dampen the effects of inertia by installing an orifice loop hose. This will bypass a small amount of oil around the motor.

Check with your individual implement manufacturer for installation instructions if this symptom appears in your application. In some applications, if you supply the vacuum motor from a power beyond connection, surging will be eliminated. The implement control valve is controlling the flow and pressure by directly sensing the load.

Note: Any combination of circuits is usually acceptable in planter applications. Make sure that any circuit that requires control of the flow is connected to No. 2 or No. 3 valve section on large tillage tractors (C Series or D Series) in planter applications. These valve sections were equipped with flow controls at the factory.

Table 11

An Air Seeder, Seed Drill, and Seed Drill with Chemical Sprayers
Application	No. 1 Valve Section	No. 2 Valve Section	No. 3 Valve Section	No. 4 Valve Section `	Power Beyond Circuit
An Air Seeder (1)	Constant down pressure or lift pressure	Markers	Additional lifting pressure	Blower (2)	-
Seed Drills (1)	Constant down pressure and lift pressure	Markers (3)	Folding Tongue	Other Lift Function	-
Seed Drills with a Chemical Sprayer (1)	Constant down pressure or lift pressure	Markers	Chemical Motor	Folding Tongue	-
Chemical Sprayer with a Following Incorporation Tool (4)	Lift Pressure	Wings	Chemical Motor (5)	Other Lift Pressure	-

( 1 )	Constant down pressure circuits cause the hydraulic system to run at maximum system pressure. If overheating occurs, consult your Caterpillar dealer for an alternative method for connecting the circuit.
( 2 )	Make sure that flow control valves on the implement are removed or make sure that the valves are opened all the way. Refer to the manual for the implement for information about the special requirements for connecting the implement to the hydraulic system. The special requirements should be used when you do not use the flow control that is supplied by the implement. Make sure that the flow control for the machine is initially set and then adjusted upward in order to attain the proper fan speed. Refer to the Operation and Maintenance Manual for information about the proper operation of the motors. If the flow to the motors is incorrect, then the flow in other circuits will be affected. The flow will be affected even if flow is not limited.
( 3 )	Make sure that you limit the flow so that the detent release works properly.
( 4 )	The motor for a chemical sprayer can be connected as a power beyond circuit. A chemical sprayer that is used on a power beyond circuit must have a flow control. The flow control should be in the line that is between the power beyond port and the motor that is for the chemical sprayer. A load sense signal line should be connected into the supply line for the motor. The load sense signal line should be connected after the auxiliary flow control by using a tee. The load sense signal line should be resolved with the rest of the valve sections that are on the valve stack.
( 5 )	Chemical motors often have an inlet orifice in the supply port to the motor. This orifice must be removed for proper operation with the tractor hydraulic system. The motors may also have a bypass valve for use with open center hydraulic systems. This valve should be turned off in order to limit the amount of flow that is needed by that circuit. This will help to reduce the buildup of heat in the system. This will also provide more flow for other circuits. Refer to the manual for the chemical motor. This manual has the necessary information that is needed to understand a hydraulic system that has the following characteristics: load sensing and closed center valve. Make sure that you understand this hydraulic system before you connect the implement to Caterpillar Agricultural Tractors.

Basic Pull Type Plate Planter

Note: This planter is the most basic pull type plate planter. The planter has lift cylinders, markers, and wings.

This planter is simple because the planter has no continuously running circuits. The circuits can be connected in any order.

Basic Pull Type Vacuum Planter

Note: This type of planter is a basic pull type vacuum planter that has lift cylinders, markers, and wings.

This planter has four or five circuits that demand oil flow. The vacuum for the system can require two motors when you operate planters that have more than twelve rows.

It is very important to keep the hoses that came from each blower motor together. The supply lines and the return lines must be connected to the same implement valve. This connection will open the spool to the tank when you actuate the pressure side of the valve.

As an alternative, you can connect the two blower motors together by using a tee. You can then run the motors by using a single implement valve. In this case, the return line should not be connected together at the implement valves. Rather, the return lines should be routed to the low pressure return port. Otherwise, the operator could start one of the two hydraulic supplies to the motor without opening the other valve that has the return line. If this happens, you will damage the motor seal.

Consequently, you should use this configuration to prevent damage to the seal and you should use this configuration to make sure that the return line is open at all times.

A Planter that is Mounted to a Three-Point Hitch

Note: This planter is a vacuum planter that is mounted on a three-point hitch. This planter also has markers and wings.

This planter has four or five circuits that demand oil flow. The vacuum can use two motors when you operate planters with more than twelve rows.

Semi-Mounted Planter

Note: The semi-mounted planter is a vacuum planter that has markers and wings.

This planter has four or five circuits that demand oil flow. The vacuum can use two motors when you operate very wide planters.

Semi-Mounted Planter with Attachments

Note: The semi-mounted vacuum planter has the following components: markers, wings, guidance and a hydraulically driven chemical pump.

This planter has six or seven circuits. There are three or four continuously running circuits: one or two motors for vacuum, chemical pump motor and guidance. The first two circuits require continuous flow.

The guidance system typically requires intermittent flow at low pressure for operation. This system drives the load sensing system to high pressure standby while the circuit is inactive. The remaining three circuits are used intermittently on the end rows.

Note: This planter will require approximately 33 to 52 L/min (8.7 to 13.7 US gpm) working through the field. The variance in the flow is due to the type of seed, the rate of delivery, and the model of the chemical pump motor. The system will be at maximum system pressure because the guidance system is connected to a valve section. In addition, the flow will be limited in the system. The flow will be limited at the end rows when you turn around the machine. You will need to keep the engine speed as high as possible in order to make sure that you have an acceptable rate of raising and lowering the implement.

Semi-Mounted Planter with Many Attachments

Note: This planter consists of the following components: markers, wings, guidance, variable seed rate and hydraulically driven chemical pump.

This planter has eight or nine circuits. There are four or five continuously running circuits: one or two motors for vacuum, chemical pump motor, variable seed rate and guidance. The first three circuits require continuous flow.

The guidance system typically requires intermittent flow at low pressure. The wings can be separated by using a left and a right control. The remaining three circuits are intermittently used on the end rows. The planter may have one to three motors. The number of motors depends on the type of variable drive of the the planter. This will make the total amount of motors used in the circuit in the range of three to six motors.

Note: This planter will require approximately 76 L/min (20 US gpm) when the planter is running through the field. The system will also be operating at maximum system pressure due to the guidance system. The operator will have the capability to limit the oil flow at the end of the rows. It is critical to maintain the engine at a high RPM in order to make sure that there is enough oil flow. This oil flow is needed in order to power the circuits that raise the implement attachments and this oil flow is needed in order to power the circuits that lower the implement attachments.

Equipment for Harvesting

Sugar Beet Harvesters

Sugar beet harvesters can be connected in numerous ways. This depends on the exact configuration.

All of the continuously running circuits are connected to the power beyond circuit or any other valve section. Be aware that this will allow the speed of the unloading conveyor to intermittently drop off, since this circuit operates at a higher pressure.

The speed of the unloading conveyor will drop off if the flow is limited by the use of other functions.

Circuits for Sugar Beet Harvesters

Guidance System

Note: A set of disks are on the front of the machine in order to provide some directional stability while you are harvesting.

Care should be taken when you use this circuit. The discs are usually bolted to the bracket for the front nose.

Excessive loads on the machine frame may be seen if the disks are pushed down all the way. The lever may be tied down so that the disks will travel further into the ground.

The circuit may have a relief valve between the ends of the cylinders. This can cause an overheating condition if you do not turn down the flow control.

Row Lift

Note: A lift cylinder is used to raise the hopper.

The pressure in the circuit for the row lift can run high because of the weight of the machine and because of the additional weight that is caused by a full hopper. The pressure could run from 10340 to 17240 kPa (1500 to 2500 psi). You can also get an overrunning condition when you lower the hopper.

One configuration that will keep the load checks from shutting off is installing an orificed check valve in the supply line. The orificed check valve will allow full flow in the raise circuit, but the valve will limit the amount of return flow in the circuit when you lower the hopper.

The orificed check valve will allow you to lower the hopper smoothly. A rapid pressure buildup, that is caused by overrunning, can cause the tips to pop out. You can prevent the tips from popping out by using an orifice check valve.

Note: Once this circuit is lowered, the circuit can be intermittently actuated in order to try to increase the depth of the hopper. This can cause the system to go to high pressure standby.

Row Finder

If the run circuit is a closed center, this system can cause the implement pump to go into high pressure standby.

Row Finder Override

This circuit is used to correct the travel of the machine when crop debris (a misaligned sugar beet) causes the harvester to move off the row. This circuit is also used at the beginning of rows in order to properly position the row lifter.

Unloading Conveyor

This system usually has two drive motors and two directional valves that are used to run the motors in the desired direction.

One conveyor loads the sugar beets into the truck or one conveyor loads the sugar beets into the hopper on the machine.

The control valve is typically a three-position, four-way valve. The center section has been set up as a closed loop.

The second conveyor motor is used to unload the hopper in each direction. Therefore, the control valve on the conveyor motor is a three-position, four-way valve. This valve has an open center position.

Flow goes from the machine to the valve for the truck loading conveyor and to the motor, if the motor is actuated. The oil then returns to the valve for the hopper conveyor.

The hopper conveyor is not running if the hopper is empty or if the hopper is full. The oil then goes through the open center position back to the machine.

Potato Harvesters

A potato harvester has the following functions:

• The motor circuit for the cleaning roller

• An unloading conveyor lift

There could be up to six additional circuits on the harvester. This depends on the level of complexity of the harvester. However, these circuits are used only at the end rows. These circuits are used to raise the digging system and guidance systems so that you can turn around. These circuits are often supplied by one valve section through the use of an auxiliary valve. These lift circuits are commonly controlled by using a remotely mounted electro-hydraulic valve, which can be supplied by No. 3 valve section.

It is very important for the customer to have the ability to adjust the flow control to the cleaning rollers ("on the go").

It is very important for the customer to have the ability to adjust the height of unloading conveyor.

Note: The demands of a large potato harvester on the power take-off (PTO) may cause the engine to lug from 1600 RPM to 1300 RPM. The amount of lug will depend on the horsepower of your machine. When this occurs, pump output flow will be reduced to 72 to 87 L/min (19 to 23 US gpm). If more flow is needed, the machine travel speed must be reduced in order to allow the engine speed to increase.

Various Attachments

Variable Rate Seed Drives

Basic Configurations

There are two basic configurations. One basic configuration consists of a single hydraulic motor that has a flow control bypass valve.

A single hydraulic motor that has a flow control bypass valve is used to power the drive speed on the seeding units. This type of system always requires the same amount of oil flow.

This type of system bypasses the oil that is not needed, even on the end rows. This type of control can also have two motors that are connected in parallel. These motors will require two times as much flow.

This configuration works best when the system is hooked up to a power beyond system. A load sense signal line can be connected to the circuit after the bypass valve and before the motor. This will keep the pump from going to maximum system pressure.

If the load sense signal line is connected before the bypass valve, the system will generate more heat as the system drives the pump to maximum system pressure.

The second basic configuration consists of one to three hydraulic motors. The motors are used to drive the seeding units. The motors are connected in series.

In this system, multiple motors can be used to turn off different planter sections. All the flow that is supplied is directed through the motor after the flow is regulated by the proportional flow control.

This circuit should be run as a power beyond circuit. The load sense signal line should be connected to the system after the proportional valve, but the load sense signal line should also be connected to the system before the motors.

Guidance Systems

Guidance systems are used to make small corrections to the implement in order to maintain correct orientation with the crop.

The guidance system has the following two common types:

• A guidance system that will shift the implement is one type of system. This system is mounted to the implement.

• A guidance system that is mounted to the three-point hitch is one type of system. The system replaces the standard quick disconnect couplers on the three-point hitch.

The guidance system consists of a row sensing device or the guidance system consists of a ridge sensing device. These sensing devices can tell whether the operator is correctly steering the machine down the row.

Once a signal is processed from the sensor a command is sent to a directional valve to direct oil at one end or the other end of a cylinder. This will shift the implement or the coupler for the three-point hitch in order to attempt to keep the implement centered on the row.

The directional valve on the guidance system should be configured as a closed center system. This will limit the flow demand. If this configuration is then connected to a valve section, the operator must be fully aware that this configuration will drive the system to maximum system pressure. The system will go to maximum system pressure when the lever is engaged in order to power the guidance system.

In order to operate this type of circuit in a better way, connect the circuit to a power beyond circuit. You should connect the load sense signal line downstream of the directional valve if no other circuit is running continuously.

Do not use a load sense signal line if a currently running circuit is generating the pressure that is needed in order to operate the guidance system.

Towed Scraper Applications

Reference: Refer to Special Instruction, SEHS9874, "Challenger Agricultural Tractors in Scraper Applications" for additional information.

Troubleshooting

Instability of Hydraulic Motor on Air Seeders or Planters

The impeller of a hydraulic motor can function similarly to a flywheel in an engine due to the inertia of the impeller. Slight variations in the flow or the pressure can cause the speed of the impeller to fluctuate or slight variations can cause the impeller to surge.

See the following suggestions in order to minimize the instability on air seeders or planters:

1. Make sure that the oil is at operating temperature.

2. Check the recommendations of the manufacturer of the implement. Some vacuum motors require special adapters such as an adapter for the drain orifice. The drain orifice is installed in a line that is located between the supply line for the motor and the return line for the motor.

   These adapters are needed when vacuum motors are used with tractors that have a closed centered load sensing feature. This feature is on Challenger Agricultural Tractors.

3. Increase the margin pressure to 2760 kPa (400 psi).

4. A different type of flow compensator spool and spring may be required in the implement valve.

   The following tractors may need a 172-9449 Valve Repair Kit to be installed:

   • Row Crop Challengers (PIN: 8DN1-UP; 1DR1-UP; 7DM1-UP; 8RD1-75; ADK1-329; ABF1-121; 3BK1-369; 6NN1-171; AEN1-460)

   • C Series tractors

   • D Series tractors

   • E Series tractors

   Reference: Refer to Special Instruction, REHS0456, "Installation of Flow Limiters and Compensator Tubes" for additional information about the installation of flow compensators.

5. On E Series tractors, replace the 152-2646 Shuttle Valve in the load sense signal line with a 9X-2614 O-Ring Face Seal Connector . The 9X-2614 O-Ring Face Seal Connector is already installed on the C Series and D Series tractors.

The Speed of the Hydraulic Motor on Air Seeders or Planters Slows When the Implement is Lowered

When a large implement is lowered, gravity is forcing a large volume of oil to the rod side of the lift system. Because of the assistance of gravity, the lift system will not generate a load signal in order to upstroke the pump for more flow.

Check the recommendations of the manufacturer of the implement. The lift system may require a one-way orifice from the manufacturer. The orifice is used in order to maintain pressure at the motor when you lower the implement.

Hydraulic Motor Seals Repeatedly Fail

There may be excessive pressure in the return line for the motor. Some manufacturers of implements require a pressure of less than 680 kPa (100 psi) in the return line.

Use the following suggestions in order to ensure that the correct pressure is in the return line for the motor:

Note: Make sure that the implement is connected properly to the tractor.

1. The supply to the motor should be connected to the retract port and the return line for the motor should be connected to the low pressure return port. Use the retract detent on the implement control lever to operate the motor.

2. Move the implement control lever to the FLOAT position in order to turn off the motor.

   Note: Moving the lever directly from the RETRACT position to the HOLD position may cause excessive pressure in the return line for the motor if a low pressure return is not used.

   Row Crop Tractors are equipped with a rotary lever locking device which will prevent the implement control lever from being moved to the HOLD position during operation of orbital motors.

   Reference: See the Operation and Maintenance Manual for additional information for your machine.

   Note: Make sure that the connection is properly connected to the tractor if a separate connection for the case drain for the motor is required. Do not connect a motor case drain directly to the return line. Make sure that the case drain oil is returned through a low pressure return.

Hydraulics Overheat While Constant Down Pressure is Not Applied to the Openers

Use the following suggestions to lower the heat in the hydraulic oil system:

1. Operate the machine at full throttle. Slower engine speeds will reduce the speed of the fan. This will significantly reduce the tractor's cooling capacity.

2. Avoid excessive steering action.

3. Make sure that the air and the oil flow through the oil coolers are not restricted.

4. If it is possible, fully open the control valve on the implement and use the control valves on the machine to control the implement.

Hydraulics Overheat While Constant Down Pressure is Applied to the Openers

Use the following suggestions to lower the heat in the hydraulic oil system:

1. Operate the machine at full throttle. Slower engine speeds will reduce the speed of the fan. This will significantly reduce the tractor's cooling capacity.

2. Avoid excessive steering action.

3. Make sure that the air and the oil flow through the oil coolers are not restricted.

4. If it is possible, fully open the control valve on the implement and use the control valves on the machine to control the implement.

5. Consult any Caterpillar dealer for an alternative method for installing the constant down pressure circuit.

Detents Disengage Before the Planter Markers Fully Unfold

In some planters, the markers are connected to the lift system. A pressure spike will kick the implement valve out of the detent position if the lift cylinders reach the end of cylinder stroke before unfolding the markers fully.

Use the following suggestions in order to prevent the detents from disengaging:

1. Adjust the flow control on the implement valve to the minimum flow that is required.

2. Adjust the detents by using the instructions in the Operation and Maintenance Manual for your tractor.

3. Hold the implement control lever until the marker is fully unfolded.

The Implement Drifts When You Road the Machine

Use the following suggestions to help prevent the implement from drifting:

1. Use No. 1 and No. 2 implement valves on early row crop tractors. No. 1 and No. 2 implement valves have load checks in order to prevent leakage. On row crop tractors that have lever release couplers, all of the valves have load checks on the return port.

2. Check the recommendations from the manufacturer of the implement. Some heavy implements may have a needle valve that is installed on the lift circuit in order to prevent drifting of the implement when you are roading the machine.

3. Make sure that you check the piston seal for leaks. The piston seal is for the lift cylinders on the implement. Replace the piston seal, if necessary.

4. Check the valve spool in the implement control valve for correct adjustment. Make sure that the valve spool is not sticking.

Synchronizing the Three-Point Hitch for Row Crop Tractors to the Lift Assist Wheels for the Planter

The hydraulic circuit for the lift assist wheels can be connected to the lift circuit for the three-point hitch. See Illustration 16 for an example of connecting a hydraulic circuit for the lift assist wheels to the lift circuit for the three-point hitch.

Illustration 16	g00741604
Hydraulic Circuit for Lift Assist Wheels

Table 12

Required Parts for Illustration 16
Item	Part Number	Description	Qty
98	6V-9844	Swivel Tee	1
99	161-8740	Valve	1
100	8C-6872	Connector	1
Q	-	Hose for lift assist wheels	1
R	-	Hose for lift cylinder	1
S	-	Supply line from valve stack	1
T	-	Hose for lift cylinder	1
U	-	Orifice (3/16 - 16)	-
V	-	Original location for plug	-
W	-	-New location for plug	-

Note: The plug that was originally in location (V) must be moved to location (W) .

If the lift assist wheels raise faster than the hitch, you may need to install smaller cylinders on the implement. A needle valve may be installed as an alternative solution to this problem. The needle valve can be used in order to adjust the lift rate on the hitch. The lift rate on the hitch can be adjusted in order to match the lift rate on the lift assist wheels. See Illustration 16 for more information about the needle valve.

If the hitch raises faster than the lift assist wheels, you may need to install larger cylinders on the implement.

Markers are too Slow Even at Full Flow

Use the following suggestions to speed up the movement of the markers:

1. Downshift the transmission at the end of the field rather than reducing the engine speed.

2. Maximum system flow may be exceeded. Turn down the flow controls on each circuit to the minimum amount that is required in order to satisfactorily operate that circuit. Reduce the number of hydraulic applications that are engaged.

3. The orifices in the hydraulic system for the marker may be too small. Install orifices that have larger diameters.