992G Wheel Loader and 854G Wheel Dozer Steering System Piston Pump (Steering) Caterpillar

Illustration 1	g01051556
A section view of the piston pump is shown above.

The rotation of the shaft is clockwise when the rotation of the shaft is viewed from the drive end.

The pump is a load sensing variable displacement piston pump.

For the test, use SAE 10 oil that is at 65 °C (149 °F).

Test at full speed:

Output ... 464 L/min (123 US gpm)

Pressure ... 690 kPa (100 psi)

Pump speed ... 1875 rpm

Engine speed ... 1750 rpm

Output ... 450 L/min (119 US gpm)

Pressure ... 6900 kPa (1000 psi)

Pump speed ... 1875 rpm

Engine speed ... 1750 rpm

Test at half speed:

Output ... 232 L/min (61 US gpm)

Pressure ... 690 kPa (100 psi)

Pump speed ... 940 rpm

Engine speed ... 875 rpm

Output ... 220 L/min (58 US gpm)

Pressure ... 6900 kPa (1000 psi)

Pump speed ... 940 rpm

Engine speed ... 875 rpm

(1) 6E-3869 Spring

Free length ... 111.09 mm (4.374 inch)

Outside diameter ... 33.8 mm (1.33 inch)

(2) 6E-1024 Pump Control Valve Gp

(3) 6E-1023 Pump Head Gp

(4) Torque for the plug ... 135 ± 15 N·m (100 ± 10 lb ft)

(5) 6E-3872 Spring

Free length ... 77 mm (3.0 inch)

Outside diameter ... 21.1 mm (0.83 inch)

(6) 6E-3334 Shim

Thickness of one shim ... 0.10 mm (0.004 inch)

6E-3335 Shim

Thickness of one shim ... 0.20 mm (0.008 inch)

6E-3336 Shim

Thickness of one shim ... 1.00 mm (0.040 inch)

Note: As required, use the shims in order to obtain dimension (A) .

(A) Dimension (A) ... 22.50 ± 0.10 mm (0.886 ± 0.004 inch)

(B) Dimension (B) ... 0.5 mm (0.02 inch)

Pump Control Valve

Illustration 2	g01052446
Pump control valve

Illustration 3	g01052450
View A-A

Maximum system pressure with the pump at rated speed ... 31000 kPa (4500 psi)

Margin pressure ... 2100 kPa (305 psi)

(7) Torque for the five bolts ... 21 ± 5 N·m (15 ± 4 lb ft)

(8) Torque for the two valve groups ... 60 ± 4 N·m (44 ± 3 lb ft)

(9) Turning the setscrew clockwise increases the system pressure. Turning the setscrew counterclockwise decreases the system pressure.

One turn of setscrew (9) will change system pressure approximately. ... 7400 kPa (1075 psi)

(10) Torque for the two locknuts ... 22 N·m (16 lb ft)

(11) 165-9383 Spring

Free length after test ... 19.4 mm (0.76 inch)

Outside diameter ... 14.6 mm (0.57 inch)

(12) 6E-3855 Spring

Length under test force ... 13.60 mm (0.535 inch)

Test force ... 92.00 ± 13.50 N (21 ± 3 lb)

Free length after test ... 17.10 mm (0.673 inch)

Outside diameter ... 8.60 mm (0.339 inch)

(13) 179-6922 Spring

Free length after test ... 20.70 mm (0.815 inch)

Outside diameter ... 13.75 mm (0.541 inch)

Pump Head

Illustration 4	g01052460

(14) Torque for four bolts ... 1000 ± 100 N·m (740 ± 75 lb ft)