AP655D Asphalt Paver Machine Systems Caterpillar

Relief Valve (Charge, Auger Conveyor and Drag Conveyor) - Test and Adjust

Usage:

Show/hide table

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.

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.

Show/hide table

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.

Show/hide table

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.

Show/hide table

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⁾	198-4238	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

Show/hide table

^( 1 )

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

Show/hide table

Table 2
Required Tools
Tool	Part Number	Description	Qty
A	8T-0855	Pressure Gauges 0 to 4000 kPa (0 to 580 psi)	2
A	6V-4144	Quick Connect Couplers	2
B	177-7860	Valved Coupler	2
	6V-4142	Fittings	2
	6V-4143	Quick Connect Couplers	2

Drive the machine to a smooth, horizontal surface.

Show/hide table




Illustration 1	g01423649

Move propulsion lever (2) to the NEUTRAL position.

Rotate speed dial (1) to the MINIMUM position.

Move parking brake switch (3) to the ON position.

[CTE_CURSOR]Move propulsion mode switch (4) to the TRAVEL position.

Show/hide table




Illustration 2	g01423657

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

Show/hide table




Illustration 3	g01423661

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 screed locks (6) .

Show/hide table




Illustration 4	g01423668

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

Show/hide table




Illustration 5	g01423678

Engage hopper lock pin (8) on both sides of the machine.

Show/hide table




Illustration 6	g01423681

Move throttle control switch (9) 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 (10) to the OFF position.

Show/hide table




Illustration 7	g01423684

Open pump compartment cover (11), which is on the right side of the machine.

Show/hide table




Illustration 8	g01423687

Remove the cap from case drain tap (12) on the left propulsion pump. Connect Tool (C) to the drain tap.

Show/hide table




Illustration 9	g01423691

Remove the cap from charge pressure tap (13) on the right material feed pump. Connect Tool (D) to the pressure tap.

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

Move engine start switch (10) 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 (9) to the HIGH IDLE position. Hold the switch in this position for less than 1 second. The engine speed should increase to 2200 rpm.

Show/hide table




Illustration 10	g01423694

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

Move throttle control switch (9) 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 (10) to the OFF position.

Show/hide table




Illustration 11	g01423702

Loosen locknut (14) on the charge relief valve on the left propulsion pump. Rotate adjustment screw (15) 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 (10) 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 (9) 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 (13).

Record the pressure at case drain tap (12).

Subtract the pressure that was recorded in Step 28 from the pressure that was recorded in Step 27. The differential pressure should be 2800 ± 172 kPa (405 ± 25 psi).

Move throttle control switch (9) 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 (10) to the OFF position.

If the pressure is within the specified range, go to Step 35. If the pressure is not within the specified range, go to Step 33.

Show/hide table




Illustration 12	g01423709

Loosen the locknut on charge relief valve (16) on the right material feed pump. In order to increase pressure, rotate the adjustment screw clockwise. In order to decrease pressure, rotate the adjustment screw counterclockwise.

Hold the adjustment screw in place, and tighten the locknut to a torque of 17 N·m (13 lb ft). Go to Step 24.

Loosen locknut (14) on the charge relief valve on the left propulsion pump. Rotate adjustment screw (15) 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 (10) 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 (9) to the HIGH IDLE position. Hold the switch in this position for less than 1 second. The engine speed should increase to 2200 rpm.

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

Record the pressure at charge pressure tap (13).

Record the pressure at case drain tap (12).

Subtract the pressure that was recorded in Step 41 from the pressure that was recorded in Step 40. The differential pressure should be 2690 ± 172 kPa (390 ± 25 psi).

If the pressure is within the specified range, go to Step 48. If the pressure is not within the specified range, go to Step 44.

Move throttle control switch (9) 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 (10) to the OFF position.

Loosen locknut (14) on the charge relief valve on the left propulsion pump. In order to increase pressure, rotate adjustment screw (15) 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 36.

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 speed dial (1) to one quarter of maximum.

Move parking brake switch (3) to the OFF position.

Slowly move propulsion lever (2) to the FULL FORWARD position. Observe the pressure at charge pressure tap (12). The pressure should momentarily decrease.

Move propulsion lever (2) to the NEUTRAL position. Then, move the lever to the FULL REVERSE position. Observe the pressure at charge pressure tap (12). The pressure should momentarily decrease.

Move propulsion lever (2) to the NEUTRAL position. Move speed dial (1) to the MINIMUM position. Move parking brake switch (3) to the ON position.

Move throttle control switch (9) 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 (10) to the OFF position.

If the flushing system operates in both directions as described, go to Step 60. If the flushing pressure does not drop in either direction, replace the flushing relief valve. If flushing pressure drops drastically in both directions, replace the flushing valve. Go to Step 57. If the flushing system does not operate properly after the flushing relief valve is replaced, the propulsion motor may have internal leakage. If the flushing system performs as described in one direction but not the other direction, check the flushing spool.

Move engine start switch (10) 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 (9) 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 49.