651E and 657E Wheel Tractor-Scrapers Auger Hydraulic System Caterpillar

Illustration 1	g00551922

When the shaft is viewed from the drive end of the piston pump, the shaft of the piston pump rotates in a counterclockwise direction.

Test at full speed

Output ... 40 L/min (10.6 US gpm)

Pressure ... 690 kPa (100 psi)

Rpm of the pump ... 2200

Output ... 38 L/min (10.0 US gpm)

Pressure ... 6900 kPa (1000 psi)

Rpm of the piston pump ... 2200

Test at half speed

Output ... 20 L/min (5.3 US gpm)

Pressure ... 690 kPa (100 psi)

Rpm of the piston pump ... 1100

Output ... 19 L/min (5.0 US gpm)

Pressure ... 6900 kPa (1000 psi)

Rpm of the piston pump ... 1100

Note: Use SAE 10W oil at 65°C (150°F) for the tests.

Maximum pump output at rated speed ... 16000 ± 350 kPa (2321 ± 51 psi)

Test conditions for the piston pump

Capacity of the piston pump ... 40 L/min (11 US gpm)

Pressure of the piston pump ... 6900 kPa (1000 psi)

RPM of the piston pump ... 2200

Note: Use SAE 10W oil at 43°C (109°F) to 49°C (120°F).

(1) Torque for the four screws ... 23 ± 2 N·m (17 ± 2 lb ft)

(2) 4T-1916 Spring

Test length ... 42.1 mm (1.66 inch)

Test force ... 65.0 ± 6.5 N (14.61 ± 1.46 lb)

Free length after the test ... 54.1 mm (2.13 inch)

Outside diameter ... 18.4 mm (.73 inch)

(3) Pressure setting of the pressure compensator valve ... 16000 ± 345 kPa (2320 ± 50 psi)

(4) 9T-4541 Spring

Test length ... 24.2 mm (.95 inch)

Test force ... 315 ± 31 N (70.8 ± 7.0 lb)

Free length after the test ... 41.2 mm (1.62 inch)

Outside diameter ... 27.8 mm (1.09 inch)

(5) Torque for the four bolts ... 38 ± 4 N·m (28 ± 3 lb ft)