Usage:
NOTE: This Program can be administered either before or after a failure. In either case the decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS4558" as the Part Number and "7755" as the Group Number. If administered before failure, use "56" as the Warranty Claim Description Code and use "T" as the SIMS Description Code. If administered after failure, use "96" as the Warranty Claim Description Code and use "Z" as the SIMS Description Code.
NOTE: This Revised Service Letter replaces the October 3, 1998 (Revised October 1998) Service Letter. Changes have been made to the Rework Procedure.
Termination Date
October 31, 1999Problem
Reworking the brake pedal pivot pin on certain IT38F Toolcarriers and 938F, 950F, 960F, 966F and 970F Wheel Loaders. corrosion and dirt build up can cause pedal sticking which results in residual brake pressure leading to elevated axle oil temperature and reduced brake life.
Affected Product
Model & Identification Number
938F (1KM1-Up)
IT38 (6FN1-Up)
950F (5SK743-Up 8TK816-Up )
960F (9ZJ1-Up)
966F (1SL507-Up 9YJ1078-Up )
970F (7SK224-Up 9JK359-Up )
Parts Needed
Action Required
See the attached Rework Procedure.
Service Claim Allowances
NOTE: This is a 5-hour job.
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
Attach.
- (1-Rework Procedure)
Rework Procedure
1. Move machine to level ground and activate the parking brake.
2. Connect the steering frame lock link.
3. Release the pressure in the hydraulic system as follows:
a. Shut off the engine.
b. Move the control levers through their full travel strokes. This will relieve any pressure that may be present in the pilot system.
c. Slowly loosen the fill cap on the hydraulic oil tank to release the pressure.
d. Tighten the fill cap on the hydraulic oil tank.
e. The pressure in the hydraulic system has now been released.
4. Put identification on all tubes, lines and hoses for installation purposes and cap all lines to prevent loss of hydraulic oil.
5. Disconnect the brake lines and wiring harness from the brake valve under the operator station.
6. Remove both the right and left brake pedal assemblies.
7. Remove the brake valve, stoplight and neutralizer switch from the left brake pedal.
8. Remove the pedal from each base assembly. If the pedals are 265mm long, shorten the heel of each pedal by 19mm to eliminate the possibility of dirt and debris buildup under pedal preventing full brake release. If the pedals are 246mm long, the heel has already been shortened and further modification is not required. See Illustration 1 for cutting instructions.
9. Using 1612304 Kit, install new pedal pivot pin and bushing in new 1611427 Right Pedal Base, using original pedal.
10. Using 1612304 Kit, install new pedal pivot pin and bushings in new 1611426 Left Pedal Base, using original pedal.
11. Reassemble stoplight switch and neutralizer switch in pedal base using new switch cam and O-ring on shaft. Note the 1056118 Neutralizer Switch is located toward the center of the pedal assembly with the 1056117 Stop Light Switch, located at the outside of the pedal assembly.
12. Reassemble brake valve to left pedal assembly.
13. Reassemble both right, left pedal assemblies and connecting 9U0773 Shaft to operator station.
14. Reassemble lines to brake valve and reconnect wiring harness. Disconnect the steering frame lock link. Bleed brakes and test operation. Replace hydraulic oil as necessary.
15. An additional hour has been allowed so the service technician can have the operator check machine and adjust neutralizer switch to operating conditions and operator preference. This process is necessary to eliminate slope "rollback" and "harshness and jerky operation" when the transmission engages and disengages. "Rollback" and "harshness and jerky operation" encourage operator to lockout transmission neutralizer causing "drive through brakes" conditions which reduces service brake life. The "Brake System Specification" module in the various service manuals describes an adjustment procedure for the neutralizer switch assembly. This procedure can also be found in Service Magazine article published 22-Jan-1996.
Illustration 1