Usage:
All Off-Highway Trucks, Quarry Trucks and Tractors
- SUPPLEMENT: MAY 10, 1999
Service Magazine SEPD0438, Article 24, Page 18, October 12, 1998; "Maximizing Off-Highway Truck Brake System Life And Improving Reliability".
Disregard these articles and refer to Service Magazine SEPD0471, Article 13, Page 15 with the same title.
--------------- END SUPPLEMENT ---------------
- SUPPLEMENT: MARCH 29, 1999
Service Magazine SEPD0438, Article 24, Page 18, October 12, 1998;
Disregard this article and refer to Service Magazine SEPD0464, Article 19, Page 14 with the same title.
--------------- END SUPPLEMENT ---------------
Description of Change: Replacement of all brake discs at time of an unscheduled repair or scheduled rebuild can lower the number of repeat failures and improve rebuild component reliability.
NOTE: Caterpillar does not recommend the reuse of worn brake discs when rebuilding any brake packs for Off-Highway Trucks or Tractors.
The reuse of worn brake discs, even those within specifications, can still cause the brake piston to stroke beyond the limits of the seals when reassembled in a brake pack. The truck will not meet the recommended daily brake check requirements published in the Off-Highway Truck Operation And Maintenance Guides.
The reuse or replacement of only a selected number of worn or damaged brake discs may result in uneven wear and unequal brake cooling flow (heat dissipation) across the reused brake discs. Unequal brake cooling oil flow may occur between the disc and plate due to the different brake cooling groove depths found in reused brake discs. The increase in brake temperature across each individual brake disc can lead to brake disc glazing, resulting in higher loads to those brake discs that were replaced at the time of rebuild. This can cause premature failure.
NOTE: Caterpillar does not recommend the reorientation of worn brake discs within the brake pack when rebuilding any brake packs for Off-Highway Trucks or Tractors.
The disassembly and reassembly of worn brake discs oriented differently within the brake pack and running on the brake hub can result in brake disc tooth damage. Brake disc teeth located over the lubrication slots of the hub will not wear the same as those located between the hub splines. When discs are reoriented, the teeth with the least wear will then become more heavily loaded and may break off from normal brake application. This practice can reduce component life and reliability.
NOTE: Caterpillar recommends the replacement of all brake discs at the time of any unscheduled or regularly scheduled wheel station assembly, brake pack component repair or rebuild.
NOTE: Caterpillar recommends using ONLY TDTO TO-4 10wt. oil in Off-Highway Truck and Tractor brake systems.
Effective with All Off-Highway Trucks, Quarry Trucks and Tractors.