Usage:
Challenger 65C (2ZJ),
Challenger 70C (2YL),
Challenger 75C (4KK),
Challenger 85C (9TK) Agricultural Tractors
Description of Change: A new brake bleeding procedure has been developed to ensure evacuation of all air in the brake system. Use this procedure in place of the service manual procedure.
Adaptable To: The new improved brake bleeding procedure is effective with Challenger 65C (2ZJ500-Up), Challenger 70C (2YL1-Up), Challenger 75C (4KK500-Up), and Challenger 85C (9TK1-Up) Agricultural Tractors.
NOTE: DO NOT USE BRAKE FLUID. Brake fluid is not compatible with the oil and seals used in the brake circuit. Seal damage will result if brake fluid is used. Use SAE 0W20 engine oil or Mercon/Dexron Automatic Transmission Fluid (ATF). Any reused oil from the brake system should be as clean as new oil. Ensure that a high level of system oil is maintained in the reservoir during and after the entire bleeding process. The best results occur when the oil is warm, minimum temperature of 20°C (68.0°F).
Illustration 1. Service brake lines and components. (A) Reservoir for master cylinder. (B) Hose assembly. (C) Elbow. (D) Bleeder Assembly. (E) Master cylinder. (F) Bleeder assembly. (G) Pressure tap. (H) Bleeder assembly.
NOTE: Step 1. is not necessary if the master cylinder has been removed and rebuilt. Instead, pump the brake pedal repeatedly to work as much air as possible out of the reservoir and into the master cylinder.
1. Disconnect hose assembly (B) at elbow (C) on top of master cylinder (E). Remove elbow (C) from master cylinder (E).
2. Fill the master cylinder (E) to top of the chamber with clean system oil. Install elbow (C) and torque to 37.5 ± 3.5 N·m (27.6 ± 2.6 lb ft). Reconnect hose assembly (B) to elbow (C)
3. Remove reservoir cap on reservoir (A) and fill to within approximately 1/2 inch of the top with clean system oil.
4. Install FT2268 Brake Bleeder Adapter in place of the reservoir cap and attach the power bleeder to it. Set the power bleeder at 206.70 kPa (30 psi).
5. Attach a 0 to 13 800 kPa (0 to 2000 psi) pressure gauge to the pressure tap (G) to monitor brake line pressure.
6. Remove the plastic cap on the bleeder assembly (F) directly above the tee fitting at the master cylinder outlet. Connect clear plastic tubing to bleeder assembly (F) and immerse the other end of the tubing below the fluid level in a clean container with system oil in it.
7. Open bleeder assembly (F) and depress the brake pedal so that the master cylinder is fully stroked, which allows air to be forced out through the bleeder assembly.
8. Continue depressing the brake pedal until all air has been bled from this location.
NOTE: Depressing the brake pedal repeatedly may be necessary to circulate the air/oil within the master cylinder to effectively bleed the system.
9. When air free oil flows through the clear plastic tubing close the bleeder assembly (F) and remove the clear plastic tubing.
10. Connect clear plastic tubing to bleeder assembly (D) on top of master cylinder (E) and immerse the other end of the tubing below the oil level in a clean container with system oil in it.
11. Depress the brake pedal just enough to get a pressure gauge reading in excess of 930 kPa (135 psi).
NOTE: Maintain this pressure. When the brake line pressure is in excess of 930 kPa (135 psi), the master cylinder should have shifted to the small cylinder.
12. Maintain the brake pedal pressure, open bleeder assembly (D) just enough to permit the brake pedal to bottom out against the stop.
13. While holding the brake pedal fully depressed, close bleeder assembly (D).
14. Release the brake pedal.
15. Repeat Steps 9, 10, 11, 12, and 13 to make certain the small chamber within the master cylinder is free of air.
16. Connect clear plastic tubing to bleeder assembly (H) and immerse the other end of the tubing below the oil level in a clean container with system oil in it.
17. Open bleeder assembly (H) and depress the brake pedal to fully stroke the master cylinder.
18. Repeatedly press the brake pedal until air free oil flows through the clear plastic tubing.
19. Continue with Step 18., but close bleeder assembly (H), then reopen 1/4turn.
20. Repeatedly press the brake pedal to fully stroke the master cylinder several times. This allows some oil to come out of the bleeder assembly (H), and at the same time, create enough pressure to move the brake piston.
21. Repeat Steps 19 and 20 until all air is bled from this point in the brake system.
22. Close bleeder assembly (H).
23. Repeat Steps 6, 7, 8, and 9.
24. Repeat Steps 10, 11, 12, 13, 14, and 15.
25. Repeat Steps 16, 17, 18, 19, 20, and 21.
26. Remove the FT2268 Brake Bleeder Adapter. Fill the master cylinder reservoir (A) and install the cap on the reservoir.
27. Replace the plastic caps to the bleeder assemblies.
NOTE: Be certain all fittings are tight to avoid leaks.
28. With engine running, depress the brake pedal several times.
NOTE: If the brake pedal feels, "spongy"check for system leaks and repeat the bleeding process.