623F Wheel Tractor-Scraper Hydraulic System Caterpillar

Illustration 1	g00444703

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

Type of pump: Piston

Note: For the testing of the pump capacity, use SAE 10W oil that is at a temperature of 65° C (150° F) .

Apply the following pressure to the pilot port. ... 1600 kPa (230 psi)

Test at full speed

Output ... 230 ± 4 L/min (61 ± 1 US gpm)

Pressure ... 6900 kPa (1000 psi)

Pump RPM ... 1900

Engine RPM ... 1900

(1) 146-3301 Pressure and Flow Compensator Valve

For information on the 146-3301 Pressure and Flow Compensator Valve , refer to Specifications, "Pressure and Flow Compensator Valve" .

(2) Torque for four bolts ... 400 ± 40 N·m (300 ± 30 lb ft)

(3) Dimension ... 0.20 ± 0.10 mm (.008 ± .004 inch)

Note: When you change the housing, recheck adjustment (3) . When you change the piston, recheck adjustment (3) . When you change a rod, recheck adjustment (3) .

In order to obtain dimension (3) , use one of the following rods.

(4) Three different rods

117-5923 Rod ... 119.3 mm (4.70 inch)

117-5924 Rod ... 119.1 mm (4.69 inch)

117-5925 Rod ... 119.5 mm (4.71 inch)

(5) 117-5926 Spring

Test force ... 29.0 ± 4.0 N (6.52 ± .91 lb)

Length under test force ... 45.0 mm (1.77 inch)

Free length ... 62.0 mm (2.44 inch)

Outside diameter ... 20.2 mm (.80 inch)

Use shims (6) to achieve dimension (D) of 132.15 ± 0.05 mm (5.202 ± .002 inch) and dimension (E) of 135.35 ± 0.15 mm (5.329 ± .006 inch) .

(6) Four different shims

Thickness

6E-0720 Shim ... 1.80 mm (.071 inch)

6E-0721 Shim ... 0.90 mm (.035 inch)

6E-0722 Shim ... 1.30 mm (.051 inch)

6E-0723 Shim ... 0.90 mm (.035 inch)

(7) Torque for the orifice ... 6.5 ± 0.2 N·m (57.53 ± 1.77 lb in)

(8) Torque for the orifice ... 6.5 ± 0.2 N·m (57.53 ± 1.77 lb in)