VALVE AS-CHECK 3453623 - Caterpillar

Testing Procedure
Hot oil and hot components can cause personal injury. Do not allow hot oil or hot components to contact skin.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat® products.Dispose of all fluids according to local regulations and mandates.
Note: Before you perform this procedure, release the pressure from the steering system and from the braking system. Also, make sure that the steering frame lock is installed.Reference: For the correct procedure for machine preparation, refer to Testing and Adjusting, "System Pressure - Release".
Illustration 1 g01440155
Left side view
Illustration 2 g01455081
Pressure ports for checking the system pressure
(1) Pressure port (rear brakes)
(2) Pressure port (front brakes) The brake manifold is located under the cab platform on the left side of the machine.
Remove the dust cap on pressure port (1) and install a 0 to 28000 kPa (0 to 4000 psi) pressure gauge.
Start the engine and allow the pump to reach the high pressure cutoff. Do not apply the service brakes. The pressure of the oil should be 13790 345 kPa (2000 50 psi).
Stop the engine. Release the pressure from the steering system and from the braking system.
Remove the dust cap on pressure port (2) and install a 0 to 28000 kPa (0 to 4000 psi) pressure gauge.
Start the engine and allow the pump to reach the high pressure cutoff. Do not apply the service brakes. The pressure of the oil should be 13790 345 kPa (2000 50 psi). Note: The oil pressure at pressure port (1) and at pressure port (2) should be similar. If the pressures at both locations are not similar, there may be a malfunctioning check valve, a loose fitting or a damaged hydraulic line.
If the pressure is within the specification, stop the engine. Release the pressure from the steering system and from the braking system and remove the pressure gauge. If the pressure is not within the specification, leave the pressure gauge connected to either pressure port and adjust the pressure compensator valve on the brake pump.Adjusting Procedure
The drive shaft rotates between the torque converter and the transmission whenever the engine is running. Contact with the rotating shaft can result in personal injury or death. The rotating shaft is located under the implement and steering pumps.Do not allow personnel into the pump bay area behind the cab when the engine is running.
Open the access doors behind the cab. The brake pump is located on the engine side of the torque converter housing.
Illustration 3 g01440158
Left side view
Illustration 4 g01444182
(3) Brake pump
(4) Pressure compensator valve
Illustration 5 g01444199
Pressure compensator valve for the brake pump
(5) Pressure compensator valve for the brake pump
(6) Cap
(7) Nut
(8) Adjustment screw
Remove cap (6) from pressure compensator valve (5).
Loosen nut (7) and rotate adjustment screw (8) by