12H, 140H, 143H, 160H and 163H Motor Graders Hydraulic and Steering System Caterpillar

Illustration 1	g00871301

For proper relief valve pressure setting, the temperature of the oil should be 49 ± 3°C (120 ± 5°F).

Relief valve pressure setting ... 27600 ± 700 kPa (4003 ± 102 psi)

Oil flow ... 2.0 ± 0.2 L/min (0.53 ± 0.05 US gpm)

Pressure change for one turn of retainer assembly (1) ... 5070 kPa (735 psi)

(2) Torque for locknut ... 20 ± 2 N·m (15.0 ± 1.5 lb ft)

Note: Hold retainer assembly (1) when you tighten locknut (2) .

(3) Washer

Outside diameter ... 12.3 mm (0.48 inch)

Inside diameter ... 5.5 mm (0.22 inch)

Thickness of washer ... 0.80 mm (0.032 inch)

(4) Spring

Test length ... 36.25 mm (1.427 inch)

Test force ... 278 ± 14 N (63 ± 3 lb)

Free length after test ... 44.12 ± 0.50 mm (1.737 ± 0.020 inch)

Outside diameter ... 12.5 mm (0.49 inch)

When you install the relief valve, lubricate seals with a thin covering of lubricant that is being sealed.