AP600D Asphalt Paver Propel System Caterpillar

Relief Valve (Charge) - Test and Adjust

Usage:

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Personal injury can result from rotating and moving parts. Stay clear of all rotating and moving parts.
Never attempt adjustments while the machine is moving or the engine is running unless otherwise specified.
The machine must be parked on a level surface and the engine stopped.

Attach a "Do Not Operate" or similar warning tag to the start switch and controls before servicing, repairing, or making adjustments to the machine.

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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	2
C ⁽¹⁾	198-4237	Pressure Sensor Gp 0 to 3500 kPa (0 to 500 psi)	1
D ⁽¹⁾	198-4238	Pressure Sensor Gp 0 to 35000 kPa (0 to 5000 psi)	1

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^( 1 )

Tool (A), Tool (B), Tool (C), and Tool (D) are part of the 198-4240 Digital Pressure Indicator .

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Table 2
Optional Tools
Tool	Part Number	Description	Qty
E	8T-0855	Pressure Gauge 0 to 4000 kPa (0 to 580 psi)	2
E	6V-4144	Quick Connect Coupler	2
F	177-7860	Hose As	2
	6V-4142	Fitting	2
	6V-4143	Quick Connect Coupler	2

Left Pump

Drive the machine to a smooth, horizontal surface.

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Illustration 1	g01534584

Move propel lever (1) to the NEUTRAL position.

Rotate propel speed dial (2) to the MINIMUM position.

Move travel mode switch (3) to the TRAVEL position.

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

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Illustration 2	g01538233

Move screed lift switch (5) to the RAISE position. Completely lift the screed.

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Illustration 3	g01534615

Engage screed lock mechanism (6) on both sides of the machine.

Move screed lift switch (5) to the FLOAT position. Allow the tow arms to rest on the screed locks.

Move screed lift switch (5) to the HOLD position.

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Illustration 4	g01538274

Move right hopper switch (8) and left hopper switch (7) to the RAISE position. Release the switches when the hopper cylinders are completely retracted.

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Illustration 5	g01538295

Engage lock pin (9) for the hopper on both sides of the machine.

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Illustration 6	g01538313

Move throttle control switch (10) 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 (11) to the OFF position.

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Illustration 7	g01538355

Open pump compartment cover (12), which is on the right side of the machine.

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Illustration 8	g01538396

Remove the cap from tap (13) for the case drain on the left propel pump. Connect Tool (C) to the tap.

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Illustration 9	g01538435

Remove the cap from charge pressure tap (14) on the right material feed pump. Connect Tool (D) to the pressure tap.

Connect one Tool (B) to Tool (C). Connect second Tool (B) to Tool (D). Connect each Tool (B) to Tool (A).

Move engine start switch (11) to the START position. Release the engine start switch when the engine starts.

Operate the engine at low idle for a few minutes.

Move throttle control switch (10) to the HIGH IDLE position. Hold the switch in this position for less than 1 second. The engine speed should increase to 2200 rpm.

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Illustration 10	g01535354

Monitor the hydraulic oil temperature on the monitor display. Operate the machine until the oil temperature reaches 43 ± 5.6 °C (110 ± 10 °F).

Move throttle control switch (10) 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 (11) to the OFF position.

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Illustration 11	g01538496

Loosen locknut (15) on the charge relief valve on the left propel pump. Rotate adjustment screw (16) for the charge relief valve clockwise by three turns. Hold the adjustment screw and tighten the locknut to a torque of 52 N·m (39 lb ft).

Move engine start switch (11) to the START position. Release the engine start switch when the engine starts.

Operate the engine at low idle for a few minutes.

Move throttle control switch (10) to the HIGH IDLE position. Hold the switch in this position for less than 1 second. The engine speed should increase to 2200 rpm.

Record the pressure at charge pressure tap (14).

Record the pressure at tap (13) for the case drain.

Subtract the pressure that was recorded in Step 29from the pressure that was recorded in Step 28. The differential pressure should be 2800 ± 172 kPa (405 ± 25 psi).

Move throttle control switch (10) 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 (11) to the OFF position.

If the pressure is within the specified range, go to Step 36. If the pressure is not within the specified range, go to Step 34.

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Illustration 12	g01538514

Loosen locknut (17) on the charge relief valve on the right material feed pump. In order to increase pressure, rotate adjustment screw (18) clockwise. In order to decrease pressure, rotate the adjustment screw counterclockwise.
Note: One turn of adjustment screw changes the pressure by approximately 152 kPa (22 psi).

Hold the adjustment screw in place, and tighten the locknut to a torque of 18 N·m (13 lb ft). Go to Step 25.

Loosen locknut (15) on the charge relief valve on the left propel pump. Rotate adjustment screw (16) for the charge relief valve counterclockwise by three turns. Tighten the locknut to a torque of 52 N·m (39 lb ft).

Move engine start switch (11) to the START position. Release the engine start switch when the engine starts.

Operate the engine at low idle for a few minutes.

Move throttle control switch (10) to the HIGH IDLE position. Hold the switch in this position for less than 1 second. The engine speed should increase to 2200 rpm.

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Illustration 13	g01535354

Monitor the hydraulic oil temperature on the monitor display. Operate the machine until the oil temperature reaches 43 ± 5.6 °C (110 ± 10 °F).

Record the pressure at charge pressure tap (14).

Record the pressure at tap (13) for the case drain.

Subtract the pressure that was recorded in Step 42 from the pressure that was recorded in Step 41. The differential pressure should be 2620 ± 170 kPa (380 ± 25 psi).

If the pressure is within the specified range, go to Step 49. If the pressure is not within the specified range, go to Step 45.

Move throttle control switch (10) 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 (11) to the OFF position.

Loosen locknut (15) on the charge relief valve for the left propel pump. In order to increase pressure, rotate adjustment screw (16) clockwise. In order to decrease pressure, rotate the adjustment screw counterclockwise.
Note: One turn of adjustment screw changes the pressure by approximately 400 kPa (58 psi).

Hold the adjustment screw in place, and tighten the locknut to a torque of 52 N·m (39 lb ft). Go to Step 37.

Test the flushing system with the following procedure.

Note: The machine will move during the flushing system test.

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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.

Rotate propel speed dial (2) to one quarter of maximum.

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

Slowly move propel lever (1) to the FULL FORWARD position. Observe the pressure at charge pressure tap (14). The pressure should momentarily decrease.

Move propel lever (1) to the NEUTRAL position. Then, move the lever to the FULL REVERSE position. Observe the pressure at charge pressure tap (14). The pressure should momentarily decrease.

Move propel lever (1) to the NEUTRAL position. Move propel speed dial (2) to the MINIMUM position. Move parking brake switch (4) to the ON position.

Move throttle control switch (10) 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 (11) to the OFF position.

If the flushing system operates correctly in both directions, go to Step 61. If the flushing pressure does not drop in either direction, replace the flushing relief valve of the left propel motor. Go to Step 58. If flushing pressure drops drastically in both directions, replace the flushing relief valve of the left propel motor. Go to Step 58. If the flushing system does not operate properly after replacing the flushing relief valve, the propel motor may be leaking internally. Check the flushing spool for the left propel motor, if the flushing system performs correctly in one direction but does not operate correctly in the other direction. Go to Step 58.

Move engine start switch (11) to the START position. Release the engine start switch when the engine starts.

Operate the engine at low idle for a few minutes.

Move throttle control switch (10) to the HIGH IDLE position. Hold the switch in this position for less than 1 second. The engine speed should increase to 2200 rpm. Go to Step 50.

Remove the tooling. Close pump compartment cover (12) .

Right Pump

Drive the machine to a smooth, horizontal surface.

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Illustration 14	g01534584

Move propel lever (1) to the NEUTRAL position.

Rotate propel speed dial (2) to the MINIMUM position.

Move travel mode switch (3) to the TRAVEL position.

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

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Illustration 15	g01534595

Move screed lift switch (5) to the RAISE position. Completely lift the screed.

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Illustration 16	g01534615

Engage screed lock mechanism (6) on both sides of the machine.

Move screed lift switch (5) to the FLOAT position. Allow the tow arms to rest on the screed locks.

Move screed lift switch (5) to the HOLD position.

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Illustration 17	g01538555

Move right hopper switch (8) and left hopper switch (7) to the RAISE position. Release the switches when the hopper cylinders are completely retracted.

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Illustration 18	g01538596

Engage lock pin (9) for the hopper on both sides of the machine.

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Illustration 19	g01538620

Move throttle control switch (10) 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 (11) to the OFF position.

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Illustration 20	g01538655

Open pump compartment cover (12), which is on the right side of the machine.

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Illustration 21	g01538973

Remove the cap from tap (13) for the case drain on the right propel pump. Connect Tool (C) to the tap.

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Illustration 22	g01538995

Remove the cap from charge pressure tap (14) on the left material feed pump. Connect Tool (D) to the pressure tap.

Connect one Tool (B) to Tool (C). Connect second Tool (B) to Tool (D). Connect each Tool (B) to Tool (A).

Move engine start switch (11) to the START position. Release the engine start switch when the engine starts.

Operate the engine at low idle for a few minutes.

Move throttle control switch (10) to the HIGH IDLE position. Hold the switch in this position for less than 1 second. The engine speed should increase to 2200 rpm.

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Illustration 23	g01535354

Monitor the hydraulic oil temperature on the monitor display. Operate the machine until the oil temperature reaches 43 ± 5.6 °C (110 ± 10 °F).

Move throttle control switch (10) 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 (11) to the OFF position.

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Illustration 24	g01539034

Loosen locknut (15) on the charge relief valve on the right propel pump. Rotate adjustment screw (16) for the charge relief valve clockwise by three turns. Hold the adjustment screw and tighten the locknut to a torque of 52 N·m (39 lb ft).

Move engine start switch (11) to the START position. Release the engine start switch when the engine starts.

Operate the engine at low idle for a few minutes.

Move throttle control switch (10) to the HIGH IDLE position. Hold the switch in this position for less than 1 second. The engine speed should increase to 2200 rpm.

Record the pressure at charge pressure tap (14) on the left material feed pump.

Record the pressure at tap (13) for the case drain on the right propel pump.

Subtract the pressure that was recorded in Step 29 from the pressure that was recorded in Step 28. The differential pressure should be 2800 ± 172 kPa (405 ± 25 psi).

Move throttle control switch (10) 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 (11) to the OFF position.

If the pressure is within the specified range, go to Step 36. If the pressure is not within the specified range, go to Step 34.

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Illustration 25	g01548794

Loosen the locknut on charge relief valve (17) on the left material feed pump. In order to increase pressure, rotate the adjustment screw clockwise. In order to decrease pressure, rotate the adjustment screw counterclockwise.
Note: One turn of adjustment screw changes the pressure by approximately 152 kPa (22 psi).

Hold the adjustment screw in place, and tighten the locknut to a torque of 18 N·m (13 lb ft). Go to Step 25.

Loosen locknut (15) on the charge relief valve for the right propel pump. Rotate adjustment screw (16) for the charge relief valve counterclockwise by three turns. Tighten the locknut to a torque of 52 N·m (39 lb ft).

Move engine start switch (11) to the START position. Release the engine start switch when the engine starts.

Operate the engine at low idle for a few minutes.

Move throttle control switch (10) to the HIGH IDLE position. Hold the switch in this position for less than 1 second. The engine speed should increase to 2200 rpm.

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Illustration 26	g01535354

Monitor the hydraulic oil temperature on the monitory display. Operate the machine until the oil temperature reaches 43 ± 5.6 °C (110 ± 10 °F).

Record the pressure at charge pressure tap (14) on the left material feed pump.

Record the pressure at tap (13) for the case drain on the right propel pump.

Subtract the pressure that was recorded in Step 42 from the pressure that was recorded in Step 41. The differential pressure should be 2620 ± 170 kPa (380 ± 25 psi).

If the pressure is within the specified range, go to Step 49. If the pressure is not within the specified range, go to Step 45.

Move throttle control switch (10) 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 (11) to the OFF position.

Loosen locknut (15) on the charge relief valve on the right propel pump. In order to increase pressure, rotate adjustment screw (16) clockwise. In order to decrease pressure, rotate adjustment screw (16) counterclockwise.
Note: One turn of adjustment screw changes the pressure by approximately 400 kPa (58 psi).

Hold adjustment screw (16) in place, and tighten locknut (15) to a torque of 52 N·m (39 lb ft). Go to Step 25.

Test the flushing system with the following procedure.
Note: The machine will move during the flushing system test.

Show/hide table

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.

Rotate propel speed dial (2) to one quarter of maximum.

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

Slowly move propel lever (1) to the FULL FORWARD position. Observe the pressure at charge pressure tap (14) on the left material feed pump. The pressure should momentarily decrease.

Move propel lever (1) to the NEUTRAL position. Then, move the lever to the FULL REVERSE position. Observe the pressure at charge pressure tap (14) on the left material feed pump. The pressure should momentarily decrease.

Move propel lever (1) to the NEUTRAL position. Move propel speed dial (2) to the MINIMUM position. Move parking brake switch (4) to the ON position.

Move throttle control switch (10) 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 (11) to the OFF position.

If the flushing system operates correctly in both directions, go to Step 61. If the flushing pressure does not drop in either direction, replace the flushing relief valve of the right propel pump. Go to Step 58. If flushing pressure drops drastically in both directions, replace the flushing relief valve of the right propel pump. Go to Step 58. If the flushing system does not operate properly after replacing the flushing relief valve, the propel motor may be leaking internally. If the flushing system performs correctly in one direction but does not perform correctly in the other direction, check the flushing spool. Go to Step 58.

Move engine start switch (11) to the START position. Release the engine start switch when the engine starts.

Operate the engine at low idle for a few minutes.

Move throttle control switch (10) to the HIGH IDLE position. Hold the switch in this position for less than 1 second. The engine speed should increase to 2200 rpm. Go to Step 50.