D5N Track-Type Tractor Hydraulic System Caterpillar

Test and Adjustment of the Pressure Reducing Valve

The pressure reducing valve is located behind an access panel on the right console of the operator station.

Illustration 1	g01072817
Right side view

Illustration 2	g01072843
(1) Accumulator (2) Manifold and reducing valve (3) Pressure reducing valve (4) Relief valve

Note: Low pilot pressure produces poor response at the pilot control levers. High pilot pressure produces extreme sensitivity at the pilot control levers.

Illustration 3	g01244342
D5N with FTC AGG1335-Up AKD1135-Up CFH0300- Up CKT0400-Up

Illustration 4	g01244345
D6N with FTC CBF0300-Up CCG0400-Up ALH0400-Up CBJ0400-Up ALR0635-Up

Illustration 5	g01241545
D6N with differential steering AKM1235-1793 ALY1335-1887 ALY1889-2065 CCK0500-0701 CBL0400-Up CCS0400-Up

Illustration 6	g01258208
D6N with differential steering AKM1794-Up ALY2066-Up CCK0702-Up

The pressure tap is located behind an access door on the right fender of the machine.

(5) Pilot supply pressure (pressure after pressure reducing valve)

1. Attach a pressure gauge to pressure tap (5) for pilot pressure on the right fender.

2. Operate the engine and exercise the implement hydraulics. The pilot pressure should be a maximum of 3275 ± 175 kPa (475 ± 25 psi).

3. If the pilot pressure is not correct, follow Steps 4 through 10 in order to adjust the pilot pressure.

4. Remove the operator's seat.

5. Remove the access panel from the right console of the operator station.

6. Loosen the locknut on the adjustment screw of pressure reducing valve (3). Turn the adjustment screw until the pilot pressure is correct.

   Note: One turn adjusts the pilot pressure by 1380 kPa (200 psi).

7. Tighten the locknut on the adjustment screw to a torque of 12 N·m (9 lb ft).

8. Remove the pressure gauge from pressure tap (5).

9. Install the access panel on the right console of the operator station.

10. Install the operator's seat.