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

Relief Valve (Charge) - Test and Adjust

Usage:

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	1
C	198-4237	Pressure Sensor Gp 0 to 3450 kPa (0 to 500 psi)	1
D	6V-9510	Plug	1
E	7J-9108	O-Ring Seal	1
F	6V-9831	Cap As	2
G	6V-8982	Elbow	1
G	7J-9108	O-Ring Seals	2
H	4C-6500	Digital Thermometer	1

Show/hide table

^( 1 )

The 198-4234 Pressure Gauge Tool Gp and the 198-4236 Adapter Cable As are part of the 198-4240 Digital Pressure Indicator .

Show/hide table

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

Show/hide table

^( 1 )

The optional tools can be used in place of the 198-4240 Digital Pressure Indicator tools which are specified in the required tool list.

Drive the machine to a smooth, horizontal surface.

Show/hide table




Illustration 1	g01216360

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.

Show/hide table




Illustration 2	g01216361

Move key start switch (7) to the OFF position.

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

Show/hide table




Illustration 3	g02036554
The upper right pump stack contains the left conveyor and the left auger pumps.

Disconnect hose assembly (9) to the left conveyor and the auger pump from tee fitting (8). Plug hose assembly (9) with Tool (D) and Tool (E). Cap tee fitting (8) with Tool (F) .

Show/hide table




Illustration 4	g02423297

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

Show/hide table




Illustration 5	g02047933

Remove the cap from case drain pressure tap (11) on the right propulsion pump. Connect Tool (C) to the case drain pressure tap.

Move key start 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).

Record the pressure at pressure tap (10).

Record the pressure at case drain pressure tap (11).

Subtract the pressure that was recorded in Step 16 from the pressure that was recorded in Step 17. The differential pressure should be 2800 ± 172 kPa (405 ± 25 psi).

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

If the pressure is not within the specified range, go to Step 21. If the pressure is within the specified range, go to Step 23.

Show/hide table




Illustration 6	g02036559

Loosen locknut (12) on the charge relief valve of the left conveyor and auger pump. In order to increase pressure, rotate adjustment screw (13) clockwise. In order to decrease pressure, rotate the adjustment screw counterclockwise.

Hold adjustment screw (13) in place. Tighten locknut (12) to a torque of 20 N·m (15 lb ft). Go to Step 13.

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

Show/hide table




Illustration 7	g02041993

Disconnect hose assembly (9) and hose assembly (14) from tee fitting (8). Cap the tee fitting with Tool (F) .

Show/hide table




Illustration 8	g02036557

Remove Tool (D) from hose assembly (9). Use Tool (G) in order to connect hose assembly (9) to hose assembly (14) .

Move key start 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).

Record the pressure at pressure tap (10).

Record the pressure at case drain pressure tap (11).

Subtract the pressure that was recorded in Step 16 from the pressure that was recorded in Step 17. The differential pressure should be 2800 ± 172 kPa (405 ± 25 psi).

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

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

Show/hide table




Illustration 9	g02036613

Loosen locknut (15) on the charge relief valve of the right conveyor and auger pump. In order to increase pressure, rotate adjustment screw (16) clockwise. In order to decrease pressure, rotate the adjustment screw counterclockwise.