HARNESS AS 8V1632 - Caterpillar

Illustration 1 g00799008
(1) Port (2) Check valve (3) Port for the pressure switch (4) Check valve (5) Pressure reducing valve (6) Relief valve (7) Tank port (8) Purge screw (9) Test port (braking system pressure) (10) Purge screw (11) Test port (pilot pressure for the hoist system) (12) Port (pilot pressure for the hoist system) (13) Port (14) Pump port
Illustration 2 g00799108
The check and pressure reducing valve is located beneath the cab.The check and pressure reducing valve divides oil flow between the accumulators for the service brakes, and the hoist control valve.Oil flows from the piston pump for the braking system to check valves (4) and (2). Check valve (4) allows oil to flow to port (13). Port (13) is connected to the brake control valve and to the accumulator for the front axle. Check valve (2) allows oil to flow to port (1). Port (1) is connected to the brake control valve and to the accumulator for the center axle. The check valves ensure that the accumulators remain charged when the pressure in the line from the piston pump drops.Pressure reducing valve (5) reduces the oil pressure to the check and pressure reducing valve that flows to the hoist control valve. This reduced pressure is pilot pressure which operates the hoist control valve.Relief valve (6) protects the system from a pressure increase if the pressure and flow compensator valve is not operating correctly.Purge screws (8) and (10) can be used in order to purge the lines to the accumulators for the braking system.Test port (9) is connected to a test fitting which allows the braking system pressure to be checked.Test port (11) is connected to a test fitting which allows the pilot pressure for the hoist system to be checked.