992G Wheel Loader Electrohydraulic System Piston Pump (Implement, Variable Displacement) Caterpillar

141-1462 Piston Pump

Illustration 1	g01049941

Variable piston pump with pressure cutoff and torque limit control

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

For the test, use SAE 10 oil that is at 65°C (150°F).

Maximum displacement for one revolution ... 250 cc (15.3 in³)

(1) 6E-3869 Spring

Free length ... 111.09 mm (4.374 inch)

Outside diameter ... 33.8 mm (1.33 inch)

(2) 6E-3872 Spring

Free length ... 77 mm (3 inch)

Outside diameter ... 21.1 mm (.83 inch)

(3) 6E-3334 Shim

Thickness of one shim ... 0.10 mm (.004 inch)

6E-3335 Shim

Thickness of one shim ... 0.20 mm (.008 inch)

6E-3336 Shim

Thickness of one shim ... 1.00 mm (.040 inch)

(4) Torque for the four bolts ... 1000 ± 100 N·m (750 ± 77 lb ft)

As required, install the shims. Use the shims to position dimension A at the correct length.

Dimension (A) ... 22.50 ± 0.10 mm (.885 ± .004 inch)

Test at full speed:

Output ... 459 L/min (122 US gpm)

Pressure ... 690 kPa (100 psi)

Pump speed ... 1875 rpm

Engine speed ... 1750 rpm

Output ... 450 L/min (118 US gpm)

Pressure ... 6900 kPa (1000 psi)

Pump speed ... 1875 rpm

Engine speed ... 1750 rpm

Test at half speed:

Output ... 229 L/min (61 US gpm)

Pressure ... 690 kPa (100 psi)

Pump speed ... 900 rpm

Engine speed ... 875 rpm

Output ... 224 L/min (58 US gpm)

Pressure ... 6900 kPa (1000 psi)

Pump speed ... 900 rpm

Engine speed ... 875 rpm

Pump displacement at torque limits

Oil pressure at 100 percent pump displacement ... 1800 kPa (260 psi)

Oil pressure at 68 percent pump displacement ... 1200 kPa (175 psi)

Oil pressure at 36 percent pump displacement ... 600 kPa (87 psi)

136-0041 Pump Control Valve

Illustration 2	g01076406

Illustration 3	g01049911

(5) Torque for the locking nut ... 28 ± 7 N·m (21 ± 5 lb ft)

(6) 107-6594 Spring

Overall length ... 19.2 mm (0.76 inch)

Outside diameter ... 11.5 mm (0.453 inch)

(7) 6E-3855 Spring

Overall length ... 17.1 mm (0.67 inch)

Outside diameter ... 8.60 mm (0.339 inch)

Spring force at 13.6 mm (0.535 inch) ... 92.0 ± 13.50 N (20.68 ± 3.035 lb)

(8) Torque for assembling the valve ... 60 ± 10 N·m (44 ± 7 lb ft)

(9) 117-7522 Spring

Overall length ... 16.75 mm (0.66 inch)

Outside diameter ... 14.7 mm (0.58 inch)

(10) Installation torque for the plug ... 105 ± 10 N·m (77 ± 7 lb ft)

(11) Torque for the locking nut ... 28 ± 7 N·m (21 ± 5 lb ft)

(12) Installation torque for the valve ... 60 ± 10 N·m (44 ± 7 lb ft)

(13) Installation torque for the plug ... 35 ± 3.5 N·m (26 ± 3 lb ft)

(14) Installation torque for the plug ... 140 ± 15 N·m (103 ± 11 lb ft)

(15) Apply 9S-3263 Thread Lock Compound to the threads for six plugs. Tighten the plugs to the following torque. ... 105 ± 10 N·m (77 ± 7 lb ft)