623F Wheel Tractor-Scraper Hydraulic System Caterpillar

Illustration 1	g00368940

Test requirements ... 49° ± 3°C (120° ± 5°F)

Pressure setting for relief valve ... 17300 ± 300 kPa (2500 ± 44 psi)

Note: The pressure setting for the main relief valve is a bench test specification. Refer to the Testing and Adjusting, "Relief Valve (Main) - Test and Adjust" for the correct pressure setting for your machine.

(1) One complete turn will change the pressure. ... 7000 kPa (1015 psi)

(2) Torque for nut ... 50 ± 7 N·m (37 ± 5 lb ft)

(3) 4T-2770 Spring

Length under test force ... 33.0 mm (1.30 inch)

Test force ... 330 ± 26 N (74 ± 5 lb)

Free length after test ... 45.8 mm (1.80 inch)

Outside diameter ... 11.2 mm (0.44 inch)

(4) 4T-1044 Spring

Length under test force ... 21.9 mm (0.86 inch)

Test force ... 53 ± 4 N (12 ± 0.9 lb)

Free length after test ... 29.6 mm (1.17 inch)

Outside diameter ... 12 mm (0.5 inch)

(5) Torque for valve ... 135 ± 15 N·m (100 ± 11 lb ft)

(6) Torque for housing ... 135 ± 15 N·m (100 ± 11 lb ft)