HARNESS AS-ENGINE 3137341 - Caterpillar

Problem
The existing brake piston may cause a build up of heat in the brake disc and may not provide as long a service life for the brake disc as desired in certain 966F and 970F Loaders.
Affected Product
Model & Identification Number
966F (4YG1-Up, 8BG1-2361 , 3XJ1-Up , 9YJ1-1187, 3FK1-Up, 1SL1-1017, 7HL1-228)
970F (7SK1-409, 9JK1-366, 7PL1-150)
Parts Needed
4 - 6I8030 Friction Disc4 - 8R9809 Seal1 - 1U8846 Gasket Maker4 - 1003596 Piston4 - 1003597 Reaction Plate4 - 1173271 Seal AssemblyAction Required
See attached rework procedure.
Service Claim Allowances
This is a 36-hour job to repair all four brakes. An additional 15 hours may be required after failure to the clean the axle housings
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
Attach.(1-Rework Procedure)Rework Procedure
The disassembly and assembly procedure is described in the Service Manual. Additional procedures for the installation of the new brake components are listed below.
The procedures listed below are for one brake. Each machine has four brakes, one for each wheel, so the procedures have to be repeated four times - once for each wheel.
1. After disassembling the axle to the point where the brake can be accessed, remove the existing 8R0942 Reaction Plate, three 8R0923 Springs, 6Y2089 Disc, and 8R0941 Piston from the brake housing. Save the reaction plate and springs for reuse.2. Thoroughly clean the seal grooves in the center housing and the mating pistons. Also be sure the seals are clean prior to installation. If there was a metal-to metal contact brake failure, a thorough cleaning of the final drive housing must be performed. Remove the carrier and planet gears to gain access for this operation.3. Install a new 8R9809 Seal and 1173271 Seal Assembly into the brake housing. Do not leave the seal assembly package open. The backup ring will shrink if it is exposed to excessive humidity or cold temperatures. Therefore, store an unopened seal assembly package in an 18 to 30° C (65 to 85° F) environment until it is used at assembly.
Axle oil may be allowed to transfer to the brake system and overfill the brake oil reservoir. This is usually caused by a twisted backup ring in the two-piece seal assembly. The backup ring can become twisted during the installation process if the inside diameter of the ring is too small, or if the piston is not pressed evenly into the bore of the axle center housing.
Before installing the seals into the center housing, check the fit of the backup ring. If the backup ring is too tight, it will not slide loosely over the piston like it should. The outside diameter can be increased by warming the seal on a heated surface or in a dry-air oven at a temperature of 40 to 60°C (104 to 140°F) for approximately five minutes. The backup ring will be loose on the piston at this point. However, if the backup ring is still too tight, it should be discarded and another backup ring should be used.
Install the seals into the center housing dry,