AP-1055D and BG-2455D Asphalt Pavers Conveyor Systems Caterpillar

Relief Valve (Charge) - Test and Adjust

Usage:

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Personal injury or death can result from sudden machine movement.
Sudden movement of the machine can cause injury to persons on or near the machine.

To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before operating the machine.

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Personal injury can result from hydraulic oil pressure and hot oil.
Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system.

Make sure all of the attachments have been lowered, and the oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.

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NOTICE

Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Caterpillar Tools and Shop Products Guide", for tools and supplies suitable to collect and contain fluids in Caterpillar machines. Dispose of all fluids according to local regulations and mandates.

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Table 1
Required Tools
Tool	Part Number	Description	Qty
A ⁽¹⁾	198-4234	Pressure Gauge Tool Gp	1
B ⁽¹⁾	198-4236	Adapter Cable As	1
C	198-4238	Pressure Sensor Gp	1
D	6V-9510	Plug	1
E	7J-9108	O-Ring Seal	1
F	6V-9831	Cap As	2
G ⁽²⁾	153-6233	Union As	1
H	4C-6500	Digital Thermometer	1

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^( 1 )	The 198-4234 Pressure Gauge Tool Gp and the 198-4236 Adapter Cable As are part of the 198-4240 Digital Pressure Indicator .
^( 2 )	The 153-6233 Union As contains the 6V-8732 Union and two 7J-9108 O-Ring Seals .

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Table 2
Optional Tools ⁽¹⁾
Tool	Part Number	Description	Qty
J	8T-0860	Pressure Gauge 0 to 40000 kPa (0 to 5800 psi)	1
K	6V-3989	Fitting	1
L	6V-4143	Quick Connect Coupler	2
M	177-7860	Hose As	1

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^( 1 )

The optional tools can be used in place of the digital pressure measurement tools which are specified in the required tool list.

Drive the machine to a smooth, horizontal surface.

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Illustration 1	g01158073

Move propulsion lever (2) to the NEUTRAL position.

Rotate speed dial (3) to the MINIMUM position.

Move parking brake switch (4) to the ON position.

Move screed lower switch (6) to the DOWN position. Lower the screed to the ground.

Move throttle control switch (5) to the LOW IDLE position. Hold the switch in this position for less than 1 second.

After the engine reaches low idle, move engine start switch (1) to the OFF position.

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Illustration 2	g01158240

Move key switch (7) to the OFF position.

Open the pump compartment, on the left side of the machine.

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Illustration 3	g01163410

Disconnect the charge supply hose to the right conveyor and auger pump at fitting (9) from tee fitting (8). Plug fitting (9) with Tool (D) and Tool (E). Cap tee fitting (8) with Tool (F) .

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Illustration 4	g01163411

Install Tool (C) on pressure tap (10). Use Tool (B) in order to connect Tool (C) to Tool (A) .

Move key switch (7) to the ON position. Move engine start switch (1) to the START position. Release the engine start switch after the engine starts.

Move throttle control switch (5) to the HIGH IDLE position. Hold the switch in this position for less than 1 second. The engine speed should increase to 2310 rpm.

Monitor the hydraulic oil temperature with Tool (J). Operate the machine until the oil temperature reaches 43 ± 5.6°C (110 ± 10°F).

With propulsion lever (2) in the NEUTRAL position and the engine at high idle, read the pressure on Tool (A). The pressure should be 2240 ± 172 kPa (325 ± 25 psi).

Stop the engine. Refer to Step 6 through Step 8.

If the pressure is not within the specified range, go to Step 18. If the pressure is within the specified range, go to Step 20.

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Illustration 5	g01163416

Loosen locknut (11) on the charge relief valve of the left conveyor and auger pump. In order to increase pressure, rotate adjustment screw (12) clockwise. In order to decrease pressure, rotate the adjustment screw counterclockwise.

Hold adjustment screw (12) in place. Tighten locknut (11). Go to Step 12.

Allow the hydraulic oil to cool before continuing with the testing and adjusting of the right conveyor and auger pump.

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Illustration 6	g01163418

Disconnect the charge supply hose at fitting (13) from tee fitting (8). Cap the tee fitting with Tool (F) .

Remove Tool (D) from fitting (9). Use Tool (G) in order to connect fitting (9) and (13) .

Move key switch (7) to the ON position. Move engine start switch (1) to the START position. Release the engine start switch after the engine starts.

Move throttle control switch (5) to the HIGH IDLE position. Hold the switch in this position for less than 1 second. The engine speed should increase to 2310 rpm.

Monitor the hydraulic oil temperature with Tool (J). Operate the machine until the oil temperature reaches 43 ± 5.6°C (110 ± 10°F).

With propulsion lever (2) in NEUTRAL and the engine at high idle, read the pressure on Tool (A). The pressure should be 2240 ± 172 kPa (325 ± 25 psi).

Stop the engine. Refer to Step 6 through Step 8.

If the pressure is not within the specified range, go to Step 29. If the pressure is within the specified range, go to Step 31.

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Illustration 7	g01163423

Loosen locknut (14) on the charge relief valve of the right conveyor and auger pump. In order to increase pressure, rotate adjustment screw (15) clockwise. In order to decrease pressure, rotate the adjustment screw counterclockwise.