69D and 769D Off-Highway Truck/Tractors and 771D Quarry Truck Power Train Caterpillar

Illustration 1	g00527710
(1) Spindle (2) Shims (3) Retainer plate (4) Bolts

Illustration 2	g00104540
Typical example Location of the purge valve for the parking brakes

Note: Before performing this adjustment, you will need to release the brakes. In order to release the parking brake, remove the purge valve from opening (A). This opening is marked with a "P". Then, connect a manual hydraulic pump or an electric hydraulic pump to opening (A). Continue to operate the pump until the brake is fully released. To learn more about releasing the brakes, refer to the information about towing that is located in the Air System and Brakes Systems Operation and Testing And Adjusting.

Adjustment Procedure

1. Thoroughly, clean all of the tapped holes in the end of spindle (1) .

2. Install retainer plate (3) with four new bolts (4) to spindle (1). Install bolts (4) so that each bolt is equally spaced around retainer plate (3) .

Note: Do not use any shims (2) at this time.

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Illustration 3	g00527711
View A-A (3) Retainer plate (4) Bolts

3. Tighten bolts (4) to a torque of 100 N·m (75 lb ft). Turn the wheel for two complete revolutions.

4. Tighten bolts (4) to 135 N·m (100 lb ft). Turn the wheel for two complete revolutions.

5. Loosen bolts (4) by 120 degrees. Turn the wheel for two complete revolutions.

6. Tighten bolts (4) to a torque of 95 N·m (70 lb ft). Turn the wheel for two complete revolutions.

7. Repeat Step 6 two more times.

8. Use a depth micrometer to determine the distance from the outside face of retainer plate (3) to the end of spindle (1). Measure the depth of the two holes that are opposite to each other on retainer plate (3). Calculate an average depth from these two measurements.

9. Use an outside micrometer to determine the thickness of retainer plate (3) at the bolt holes. Measure the thickness of retainer plate (3) at the same locations that were used in Step 8. Calculate an average thickness from these two measurements.

10. Find the gap between the end of spindle (1) and the inside face of retainer plate (3). To find this gap, subtract the dimension that was found in Step 9 from the dimension that was found in Step 8.

11. Calculate the shim pack thickness. Add 0.178 mm (0.0070 inch) to the distance that was found in Step 10.

12. Assemble shim pack (2). The shim pack thickness should be the value that was found in Step 11 within + 0.000 - 0.050 mm (+ 0.000 - 0.0020 inch). Remove bolts (4) and retainer plate (3) .

13. Install shim pack (2) .

14. Install retainer plate (3) over shim pack (2). Install eight new bolts (4).

15. Evenly torque opposite bolts (4) to 250 ± 15 N·m (185 ± 10 lb ft).