621H, 623H, and 627H Wheel Tractor-Scrapers Hydraulic and Steering System Caterpillar

Illustration 1	g02392058

(1) Torque for screws ... 18 ± 2.5 N·m (159 ± 22 lb in)

(2) 6D-1601 Spring

Test length ... 40.4 mm (1.59 inch)

Test force ... 28.0 ± 2.2 N (6.30 ± 0.50 lb)

Free length after test ... 53.8 mm (2.12 inch)

Outside diameter ... 15.7 mm (0.62 inch)

(3) 3H-2549 Shim

Thickness ... 0.25 mm (0.010 inch)

Pressure change for one shim ... 190 kPa (28 psi)

(4) 3J-7470 Shim

Thickness ... 1.20 mm (0.048 inch)

Pressure change for one shim ... 55 kPa (8 psi)

Note: As required, use shim (3) and shim (4) in order to set the pressure for the pressure reducing valve.

(5) 8J-0245 Spring

Color code ... yellow stripe

Test length ... 34.04 mm (1.34 inch)

Test force ... 45 ± 6 N (10.2 ± 1.3 lb)

Free length after test ... 42.06 mm (1.656 inch)

Outside diameter ... 11.91 mm (0.469 inch)

(6) Spacers

Thickness of one 8M-8211 Spacer ... 0.25 mm (0.010 inch)

Thickness of one 7M-8538 Spacer ... 0.90 mm (0.035 inch)

Note: As required, use spacers (7) to set the flow control valve.

(7) 6J-7240 Spring (OUTER)

Test length ... 47.5 mm (1.87 inch)

Test force ... 221 ± 18 N (50 ± 4 lb)

Free length after test ... 60.33 mm (2.375 inch)

Outside diameter ... 30.48 mm (1.200 inch)

(8) 8J-2634 Spring (INNER)

First Test

Test length ... 62.5 mm (2.46 inch)

Test force ... 115 ± 23 N (25.77 ± 5.11 lb)

Second Test

Test length ... 42.16 mm (1.66 inch)

Test force ... 435 N (97.78 lb)

Free length after test ... 69.9 mm (2.75 inch)

Outside diameter ... 20.62 mm (0.812 inch)

(9) 4F-7115 Spring

Color code ... brown stripe

Test length ... 34.1 mm (1.34 inch)

Test force ... 225 N to 260 N (50.1 lb to 58.8 lb)

Free length after test ... 42.9 ± 1.6 mm (1.69 ± 0.06 inch)

Outside diameter ... 11.91 mm (0.469 inch)

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

(11) 2L-9625 Spring

Test length ... 55.09 mm (2.169 inch)

Test force ... 238 ± 18 N (54 ± 4 lb)

Free length after test ... 69.85 mm (2.750 inch)

Outside diameter ... 52.99 mm (2.086 inch)

(12) Shims

Thickness of one 8B-3115 Shim ... 0.25 mm (0.010 inch)

Thickness of one 1U-4714 Shim ... 0.12 mm (0.005 inch)

Note: As required, use shims (12) to balance the cylinder pressure.