Introduction
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| Illustration 1 | g00460114 |
Implement Hydraulic System (1) Three-point hitch control valve (2) Three-point hitch relief valve (3) Implement control valves (4) Orifice (5) Lube line for the power take-off bearing (6) Implement filter (7) Bypass valve (8) Line to the charge circuit for the steering pump (9) Line from the small section of the tandem charge pump to the charge circuit for the transmission (10) Tandem charge pump (11) Suction screen (12) Common sump (13) Regulator valve (14) Steering pump (15) Pump drive housing (16) Implement hydraulic pump (17) Three-point hitch cylinders (18) Inlet manifold (19) Load check valves (20) "+" quick coupler port for extended cylinder and "-" quick coupler port for retracted cylinder (AA) Supply oil (BB) Oil from the small section of the tandem charge pump (DD) Pilot signal oil (EE) Oil from the large section of the tandem charge pump (HH) Blocked oil (LL) Sump oil | |
The hydraulic system provides a controlled flow of oil to the user supplied implements and the three-point hitch.
The implement hydraulic system is a closed center, load sensing hydraulic system. The hydraulic system compensates for the flow and for the pressure. The design permits feedback from the requirements of the implement hydraulic system to a compensator valve that is located on the implement hydraulic pump.
The compensator valve signals the pump in order to deliver the flow and the pressure that is necessary in order to satisfy the requirements of the implement hydraulic system. The signal is the maximum load pressure that is measured at the work ports of the implement control valves.
The transmission of the load sensing signal to the implement hydraulic pump occurs through the pump signal control network. The pump signal control network consists of a series of resolvers, ports, and lines.
If the three-point hitch and various implements are not being used, the flow of the implement hydraulic pump is reduced to 2.3 L/min (0.6 US gpm). This reduced oil flow is called the pump case drain. Also, the implement hydraulic pump maintains a minimum standby pressure of 2070 kPa (300 psi).
The implement hydraulic system shares a common sump (12) with all hydraulic systems. Oil is filtered through a 250 micron suction screen (11) before exiting the oil sump.
Additional filtration is obtained by independent in-line filters for the implement hydraulic system and the steering hydraulic system.
The sump includes the following components: center housing, extension housing and transmission. The two bolted joints that are between these three components must be sealed with 6V-6640 anaerobic sealant in order to ensure that no leaks occur.
Component Location
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| Illustration 2 | g00471043 |
Component Locations (1) Three-point hitch control valve (2) Three-point hitch relief valve (3) Implement control valves (6) Implement filter (7) Bypass valve (10) Tandem charge pump (11) Suction screen (12) Common sump (13) Regulator valve (14) Steering pump (15) Pump drive housing (16) Implement hydraulic pump (17) Three-point hitch cylinders (20) "+" quick coupler port for extended cylinder and "-" quick coupler port for retracted cylinder (21) Compensator valve (22) Transmission filter (23) Steering filter (24) Steering motor (25) Oil cooler (26) Diverter valve (27) Pilot valve (28) Brake valve (29) Power take-off (30) Solenoid for the power take-off (31) Valve for the creeper transmission (32) Transmission hydraulic control | |
The implement hydraulic system and the three-point hitch include the following components:
- The right hand control module is located inside the right side console. The module for electronic draft control is located on the floor behind the seat.
- The implement filter is located on the left side of the extension housing.
- The implement hydraulic pump is located on the rear of pump drive housing (15) .
- The implement control valves are located at the rear of the machine behind the cab.
- The quick couplers are mounted to the individual implement control valves.
- The three-point hitch and the cylinders are located below the implement control valves.
Implement Hydraulic System
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| Illustration 3 | g00471044 |
(10) Tandem charge pump (12) Common sump (13) Regulator valve (14) Steering pump (15) Pump drive housing (16) Implement hydraulic pump (21) Compensator valve (33) Case drain oil line | |
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| Illustration 4 | g00461954 |
(A) Dipstick (B) Filler tube | |
Oil from common sump (12) is supplied to tandem gear pump (10) which moves oil through the filter to the pump inlet. Pressure regulating valve (13) maintains a positive inlet pressure to the steering pump and the implement hydraulic pump.
Implement hydraulic pump (16) has the following characteristics: variable displacement, load sensing, compensation for pressure and compensation for flow. This piston type pump has variable flow and pressure. The flow and pressure are dependent on the system demands that are sensed by compensator valve (21) .
The inlet for the implement hydraulic pump is charged by part of the flow from the large section of tandem charge pump (10). Tandem charge pump (10) produces a flow of 121 L/min (32 US gpm) at rated speed.
Compensator valve (21) is mounted on top of the implement hydraulic pump. The compensator valve is designed to maintain the pump outlet pressure at approximately 1830 kPa (265 psi) above the load requirements.
The compensator valve also limits the maximum system pressure to 18950 ± 345 kPa (2750 ± 50 psi). If an implement is suddenly stalled, the compensator valve limits the pump outlet pressure to maximum system pressure.
All of the implement control valves are in the HOLD position during a no-load condition. The system pressure is at low pressure standby which is approximately 2070 kPa (300 psi). The closed center implement control valve works with the pressure compensator valve in order to control oil flow. The constant oil flow provides a constant speed for the implement under varying working loads.
Implement hydraulic pump (16) has a case drain flow up to approximately 2.3 L/min (0.6 US gpm). The case drain oil flows through case drain oil line (33). Oil from case drain oil line (33) is routed to pump drive housing (15).
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| Illustration 5 | g00460910 |
Pump arrangement (10) Tandem charge pump (14) Steering pump (15) Pump drive housing (16) Implement pump (33) Case drain oil line (34) Idler gear (35) Long bolt | |
The suction tube draws oil from two sources. One source of oil is drawn through the 250 micron suction screen (11). The suction screen is mounted sideways in the lower portion of the center housing.
The suction screen is threaded onto a mounting stud that is on the left side of the center housing.
A heater element for the hydraulic oil replaces the mounting stud when the machine is equipped with the optional package for cold weather starting.
Suction screen (11) is supported by a bore in the center housing on the right side. The right end of the suction screen has an O-ring seal. The O-ring seal only allows oil that is drawn through the screen to enter the pump inlet cavity.
The suction screen does not extend into the inlet of the cavity.
Note: Do not attempt to remove the mounting stud or the optional heater element while the suction screen is in place. The suction screen will drop into the common sump, which may damage the screen.
The second source of supply oil is return oil from the charge circuit for the implement hydraulic pump. Charge oil that is not used by the implement hydraulic pump is routed to the pump inlet cavity for the supply tube through a return line.
The return line is connected to the end cover.
Note: The oil in the return line is not oil that is being returned from the implement control valves. The return oil is filtered oil that was not used to charge the inlet port of the implement hydraulic pump.
The end cover contains a regulator valve in the inlet for the return line. The regulator valve creates a positive back pressure of 104 ± 34 kPa (15 ± 5 psi) to the inlet opening of the implement hydraulic pump.
The pressure is dependent upon the amount of oil that is passing through the valve. The back pressure at the inlet for the implement hydraulic pump helps prevent cavitation.
The long bolt (35) on the back side of the pump drive gear holds the live gear for the PTO drive shaft in place if the rear PTO shaft is removed. The bolt will prevent the live gear from falling into the common sump.
Pump Drive
Implement hydraulic pump (16) and steering pump (14) are mounted on pump drive housing (15) that is bolted on the right side of the center housing.
The pump drive gear is driven by an idler gear (34). Idler gear (34) is driven from a live gear that is mounted on the PTO drive shaft.
The drive gear for the pumps is supported by tapered roller bearings. Oil from case drain oil line (33) is used for splash lubrication for the pump drive housing (15) .
The tandem charge pump (10) is driven through steering pump (14). The steering pump is mounted to the front of pump drive housing (15) .
Charge Oil Circuit
Oil to all various machine systems is supplied by tandem charge pump (10) that is driven through steering pump (14) .
Tandem charge pump (10) is a gear type pump. The pump consists of a small section that contains the transmission pump. Also, the pump has a large section that contains the charge pump for the implement hydraulics and the steering hydraulics.
The tandem charge pump has a common supply tube that is connected to the sump in the center housing. Oil flows through a 250 micron suction screen (11) that is mounted sideways in the sump.
An optional heater element for the hydraulic oil may be mounted inside suction screen (11) .
The smaller section of the pump supplies charge oil to the following components: transmission hydraulic control, lubrication of the transmission, PTO control, service brake control and hydraulic oil cooler. The transmission charge pump produces a flow of 115 L/min (30 US gpm) at rated engine speed. The pressure of the oil is 2070 kPa (300 psi).
The larger section of the pump supplies charge oil to the implement and steering systems. The charge pump produces a flow of 218 L/min (58 US gpm) at rated engine speed. The pressure of the oil is 690 kPa (100 psi).
Regulator valve (13) in the return line at suction screen (11) maintains a pressure of 104 ± 34 kPa (15 ± 5 psi) to the inlet of the implement hydraulic pump. The positive pressure at the inlet helps prevent cavitation of the implement hydraulic pump.
Implement and Steering Filters
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| Illustration 6 | g00471109 |
(6) Implement filter (23) Steering filter | |
Oil that is from the large section of the tandem charge pump is routed to the left side of the machine. Oil flow is divided between the implement and steering systems. Implement oil is routed rearward and steering oil is routed forward.
The implement hydraulic system is protected by a 13 micron filter with a bypass valve. The bypass valve opens at 172 kPa (25 psi). The bypass valve contains an electronic filter bypass switch.
If the bypass valve opens allowing unfiltered oil into the implement system for more than 8 seconds, the filter bypass switch signals the Electronic Monitoring Center. A red indicator lamp will flash on the EMC. The audible alarm will sound one beep. Also, a F392 fault code will be logged. The F392 fault code indicates a restriction in the transmission filter or in the implement filter.
If the temperature of the sump oil is less than 38°C (100°F), the red indicator lamp flashes and one audible beep is sounded. No fault code will be logged.
The bypass valve for the steering hydraulic system is identical to the bypass valve for the implement hydraulic system. The steering filter (23) is physically smaller than the implement filter (6). The steering filter (23) is the same filter element as transmission filter (22) .
If a bypass of the steering filter occurs for more than 8 seconds, the red indicator lamp will remain illuminated. Also, an audible alarm sounds and a critical fault code F391 is logged.
A red indicator lamp that is illuminated consistently indicates a steering filter that is becoming plugged. A critical alarm will sound. This will occur for 90 seconds. The word "STOP" will then flash for 30 seconds before automatic engine shutdown occurs. An automatic engine shutdown does not occur if the temperature of the sump oil is below 20°C (68°F). Only the red indicator lamp will flash when sump oil is below 20°C (68°F).
Implement Hydraulic System
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| Illustration 7 | g00603114 |
(1) Three-point hitch control valve (6) Implement filter (10) Tandem charge pump (11) Suction Screen (12) Common sump (13) Regulator valve (17) Three-point hitch cylinders (18) Inlet manifold (19) Load check valves (20) "+" quick coupler port for extended cylinder and "-" quick coupler port for retracted cylinder (21) Compensator valve (36) Lube line to the bearing for the PTO (AA) Supply oil (BB) Oil from the small section of the tandem charge pump (DD) Pilot signal oil (EE) Oil from the large section of the tandem charge pump (HH) Blocked oil (LL) Sump oil | |
Oil flows from common sump (12) through the 250 micron screen (11) to tandem charge pump (10). Charge oil from the larger section of the tandem charge pump provides oil for both the implement and steering circuits.
Charge oil for the implement circuit flows through 15 micron filter (6) to the inlet of the implement hydraulic pump. Charge oil for the inlet of the implement hydraulic pump also lubricates a bearing for the PTO drive shaft. Lube line (36) is routed into the extension housing. The bearing that is located at the connection of the front drive shaft and the rear drive shaft is lubricated by lube line (36) .
A positive charge pressure for the implement hydraulic pump is maintained by regulating valve (13). Regulating valve (13) is located in the inlet for the return line. Oil that is not used in the charge circuit for the implement pump is dumped across the regulating valve and back into the inlet for the tandem charge pump.
Output oil from the implement hydraulic pump is called supply oil. This supply oil is routed to inlet manifold (18) of the implement control valve bank. Internal passages through each implement control valve make flow available to the implement control valves and the three-point hitch control valve.
Three implement control valves are standard equipment. The fourth implement control valve is available as an attachment.
The oil for the pump signal control network originates in the implement control valve bank. The pump signal control network flows through all of the individual valve bodies to the inlet manifold, and then to pump compensator valve (21) .
The pump signal control network descends through the implement control valve bank in the following order: three-point hitch valve, #4 implement control valve (if equipped), #3 implement control valve, #2 implement control valve and #1 implement control valve.
The return oil from the implement control valve bank flows through inlet manifold (18). Next, the return oil flows through a return tube to the inlet of the suction screen that is in the common sump. The return tube helps prevent oil aeration when the system has high demands.
Supply oil from the implement control valves is directed to quick couplers (20) and three-point hitch cylinders (17) .
#1 implement control valve and #2 implement control valve contain load check valves (19). Load check valves (19) prevent implement drift while the implement control lever is in the HOLD position.
Implement Hydraulic Circuit (PIN: 8DN1-983; 1DR1-2037; 7DM1-1494)
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| Illustration 8 | g00354055 |
The # 1 implement control valve has flow priority over the other implement control valves and the three-point hitch. The flow priority allows implements to have hydraulic flow that is constant regardless of the other flow demands that are on the system. The #1 implement control valve is not affected by upstream pressures. Adjust the flow control for the minimum amount that is required by the implement. The remaining oil flow can then supply the rest of the circuits.
The three-point hitch has priority once the demands of the #1 implement control valve is met. The remaining circuits are supplied in the following order: #4 implement control valve (if equipped), #3 implement control valve and #2 implement control valve.
Implement Hydraulic Circuit (PIN: 8DN984-UP; 1DR2038-UP; 7DM1495-UP)
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| Illustration 9 | g00445210 |
All of the implement control valves and the three-point hitch have an equal opportunity in order to obtain oil flow. The determining factor is the resolved pressure of each individual implement control valve. None of the implement control valves has a flow priority. If the flow demand is greater than the flow that can be supplied by the pump, the circuits with the lowest pressure will be satisfied first. The circuits with the highest pressures will be satisfied last. Pump output varies with engine speed. Reducing the engine speed will reduce the available hydraulic flow. If necessary, increase the engine speed in order to produce sufficient oil flow when you simultaneously operate the three-point hitch and the implement hydraulics.
Adjustment of Flow Control (PIN: 8DN1-551; 1DR1-1156; 7DM1-388)
The adjustment for the flow control of each implement control valve is located on the right side of the implement control valve bank just behind the control cables. Each implement control valve can be adjusted in order to provide a flow of 3.8 to 93 L/min (1.5 to 24 US gpm).
Adjustment of Flow Control (PIN: 8DN552-983; 1DR1157-2037; 7DM389-1494)
Each implement control valve has a hydraulic flow control in the cab. The flow controls are located on the right side of the cab behind the operator's seat.
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| Illustration 10 | g00343017 |
Turn the flow control in the counterclockwise direction in order to increase the flow. Turn the flow control in the clockwise direction in order to decrease the flow. Each implement control valve can be adjusted in order to provide a flow of 3.8 to 93 L/min (1.5 to 24.5 US gpm).
Adjustment of Flow Control (PIN: 8DN984-UP; 1DR2038-UP; 7DM1495-UP)
Each implement control valve has a hydraulic flow control in the cab. The flow controls are located on the right side of the cab behind the operator's seat.
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| Illustration 11 | g00445346 |
Turn the flow control in the counterclockwise direction in order to increase the flow. Turn the flow control in the clockwise direction in order to decrease the flow. Each implement control valve can be adjusted in order to provide a flow of 3.8 to 114 L/min (1.5 to 30 US gpm).
Implement Controls
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| Illustration 12 | g00462824 |
(37) Implement control levers (38) Rotary lever locking device (I) #1 implement control lever (green stripe) (II) #2 implement control lever (blue stripe) (III) #3 implement control lever (brown stripe) (IV) #4 implement control lever (gray stripe) | |
Implement control levers (37) for the implement control valves are located in the right hand console of the cab. Each implement control lever is coded with a colored stripe in order to match the color coded decal by the implement valve bank at the rear of the machine.
Each implement control lever has the following four detents: RAISE, HOLD, LOWER and FLOAT. The RAISE and LOWER positions have an automatic kickout for the detent.
From the HOLD position, the implement control lever is pulled toward the operator for the EXTEND position. The implement control lever is pushed away from the operator for the LOWER position and FLOAT position.
Each implement control lever has a rotary lever locking device. Use the rotary lever locking device in order to lock out certain functions of the implement control lever.
The rotary lever locking device has four positions: HOLD, FLOAT, FULL TRAVEL and EXTEND.
Rotate lever locking device (38) all the way in the clockwise direction in order to lock out implement control lever (37) from the following positions: EXTEND, RETRACT and FLOAT.
Rotate lever locking device (38) by one notch in the counterclockwise direction in order to lock out the FLOAT position.
Rotate lever locking device (38) by one additional notch in the counterclockwise direction in order to allow the implement control lever to travel through all the positions.
Rotate lever locking device (38) all the way in the counterclockwise direction in order to lock out the following positions: HOLD and EXTEND. Use this position when you operate hydraulic motors.