793B Off-Highway Truck Air System and Brakes Caterpillar

Illustration 1	g00762288

Rotation of the pump is counterclockwise when the pump is viewed from the drive end.

Lubricate the pump with oil before you operate the pump.

Bench test requirements: SAE 10W oil must be stabilized at 65°C (150°F) before the test is performed.

(A) Torque converter scavenge section

Minimum output ... 40 L/min (10.6 US gpm)

Test pressure ... 345 kPa (50 psi)

Test speed of pump ... 900 rpm

(B) Torque converter charging section

Minimum output ... 197 L/min (52.0 US gpm)

Test pressure ... 1035 kPa (150 psi)

Test speed of pump ... 900 rpm

(C) Parking brake release section

Minimum output ... 33 L/min (8.7 US gpm)

Test pressure ... 4136 kPa (600 psi)

Test speed of pump ... 900 rpm

(D) Brake cooling section

Minimum output ... 115 L/min (30.4 US gpm)

Test pressure ... 345 kPa (50 psi)

Test speed of pump ... 900 rpm

Note: Prior to testing the pump, the pump must rotate freely by using your hand.

(1) Torque for the locknut on the pump drive gear ... 110 ± 13 N·m (81.1 ± 9.6 lb ft)

(2) Clearance between a new gear and a new cover ... 0.104 ± 0.043 mm (0.0041 ± 0.0017 inch)

(3) Clearance between a new gear and a new body ... 0.163 ± 0.038 mm (0.0064 ± 0.0015 inch)

(4) Clearance between a new gear and a new body ... 0.086 ± 0.026 mm (0.0034 ± 0.0010 inch)

(5) Dimensions of new shafts and of new pump bodies

Diameter of the drive shafts and diameter of the driven shafts ... 31.742 ± 0.005 mm (1.2497 ± 0.0002 inch)

Diameter of the bores in the pump body ... 31.786 ± 0.008 mm (1.2514 ± 0.0003 inch)

(6) Clearance between a new gear and a new cover ... 0.125 ± 0.038 mm (0.0049 ± 0.0015 inch)

Illustration 2	g00762466

(7) Location of the bearing joint from the vertical centerline ... 30 ± 15 degrees

(8) Depth of the two bearings into cover ... 1.57 ± 0.25 mm (.062 ± .010 inch)

Illustration 3	g00762468

(9) Measurement from the end of the four dowels to the face of the body ... 5 ± 0.5 mm (0.20 ± 0.02 inch)

Illustration 4	g00762471

(10) Location of the bearing joint from the vertical centerline ... 30 ± 15 degrees

(11) Depth of two dampers (E) into the body ... 7.5 ± 0.5 mm (0.30 ± 0.02 inch)

(12) Depth of the two bearings into the body ... 1.5 ± 0.25 mm (0.06 ± 0.010 inch)

(13) Depth of the four dampers (F) into the body ... 1.5 ± 0.5 mm (0.06 ± 0.02 inch)

Illustration 5	g00762472

(14) Measurement from the end of the four dowels to the face of the body ... 4.83 ± 0.5 mm (.190 ± .02 inch)

Illustration 6	g00762474

(15) Depth of the two bearings into the cover ... 1.50 ± 0.5 mm (0.060 ± 0.02 inch)

(16) Location of the bearing joint from the vertical centerline ... 30 ± 15 degrees

Illustration 7	g00762475

(17) Location of the bearing joint from the vertical centerline ... 30 ± 15 degrees

(18) Depth of the two bearings into the cover ... 1.50 ± 0.5 mm (0.060 ± 0.02 inch)

(19) Measurement from the end of the two dowels to the face of the cover ... 6 mm (0.24 inch)

Illustration 8	g00762476

(20) Depth of the two bearings into the cover ... 1.50 ± 0.25 mm (0.060 ± 0.010 inch)

(21) Location of the bearing joint from the vertical centerline ... 30 ± 15 degrees