69D and 769D Off-Highway Trucks and 771D Quarry Truck Steering System Caterpillar

Illustration 1	g00519251

Illustration 2	g00519299

Rotation of the pump is clockwise when the pump is viewed from the drive end.

Type of pump: Variable Displacement Piston Pump

Bench test requirements:

Oil ... SAE 10W

Stabilized oil temperature ... 60 °C (140 °F)

Note: Use a bench test to accurately set the margin pressure.

Margin pressure

Pressure setting ... 3275 ± 105 kPa (475 ± 15 psi)

Pump speed ... 2000 rpm

Pump flow ... 75 L/min (20 US gpm)

Discharge pressure ... 15000 kPa (2175 psi)

Maximum standby pressure ... 4800 kPa (695 psi)

Pressure compensation at zero flow ... 23500 ± 350 kPa (3410 ± 50 psi)

Note: Maximum pump stroke is obtained by applying the discharge pressure to the load sensing port even at standby pressure.

Test at Full Speed

Test speed of pump ... 2100 rpm

Discharge pressure ... Standby pressure

Pump output flow at maximum pump stroke ... 155.4 ± 6.2 L/min (41.1 ± 1.6 US gpm)

Test speed of pump ... 2100 rpm

Discharge pressure ... 15000 kPa (2175 psi)

Pump output flow at maximum pump stroke ... 155.4 + 1.6 - 10.9 L/min (41.1 + 0.4 - 2.9 US gpm)

Test at Half Speed

Test speed of pump ... 1050 rpm

Discharge pressure ... Standby pressure

Pump output at maximum pump stroke ... 77.7 ± 3.1 L/min (20.5 ± 0.8 US gpm)

Test speed of pump ... 1050 rpm

Discharge pressure ... 15000 kPa (2175 psi)

Pump output at maximum pump stroke ... 77.7 + 0.8 - 5.4 L/min (20.5 + 0.2 - 1.4 US gpm)

(1) Torque for four bolts ... 165 ± 30 N·m (122 ± 22 lb ft)

(2) Torque for plug ... 105 ± 10 N·m (77 ± 7 lb ft)

(3) Assemble the ring with the gap over the weep hole.

(4) Assemble the inner seal onto the shaft with the spring loaded side of the seal toward the bearing.

(5) Assemble the outer seal onto the shaft with the spring loaded side of the seal toward the splines.

(6) Torque for plug ... 45 ± 5 N·m (400 ± 45 lb in)

(7) 6E-4000 Spacer

Thickness ... 3.0 mm (0.12 inch)

Note: Grind spacer (7) to the required thickness. The faces of the spacer must be parallel. The tolerance of the faces of spacer (7) is 0.05 mm (0.002 inch).