COUPLING GP-PUMP 7Y0872 - Caterpillar

Do not use the additive for brake chatter without checking the machine for a more serious problem.
Refer to the following list of potential serious problems that may cause brake chatter.
Water or antifreeze in the axle oil Concentrations of 0.5% or greater can significantly raise the static coefficient of friction of the brakes. This static coefficient of friction may cause chatter. Concentrations of 0.5% or greater can cause swelling of the brake friction material and separation from the discs core. Drain the compartment and flush the compartment as soon as possible. Monitor brake disc wear and watch for elevated iron in the S O S Oil Analysis.
Degradation of axle oil If the oil is used beyond the wear life, the friction modifiers may be depleted. This depletion may initiate brake chatter. Oil degradation can result in rapid brake wear and the reduction in protection of the oil film thickness for the gears and the bearings. Wear life of the oil will vary depending on the application and operator techniques. Monitor the levels of contaminant in the oil. Monitor the oil condition by using S O S Oil Analysis to develop the best oil change interval for the machine. Never use oil beyond the scheduled maintenance interval that is recommended by Caterpillar.
Axle oil can become oxidized or burnt. When oil becomes oxidized, the friction modifiers are depleted. This depletion of friction modifiers may cause brake chatter. Excessive oil temperatures will produce rapid brake wear and reduced protection in oil film thickness for gears and for bearings. Correct the problem that is producing excessive oil temperature, or change the axle oil more frequently to sustain good oil condition.
Brake discs worn beyond maximum allowable condition. When the friction material of the brake disc is worn to the bonding material or the core, the coefficients significantly change. This change will increase the probability of brake chatter.
Unapproved oil Gear lube is one example of unapproved oil. Most gear lube contains extreme pressure additives. Extreme pressure additives that are combined with elevated brake temperatures can glaze the surface of the friction material. As a result, the dynamic coefficient is reduced and the probability of chatter is increased. Drain and flush the compartments. Remove all gear lube. Replace the wheel brake friction pad with a new pad.Another example of unapproved oil is Final Drive Oil for the Axle. 1U-9891 Hydraulic Oil Additive will not effectively eliminate brake chatter if the FDAO is mistakenly used.Reference: Refer to the machine Operation and Maintenance Manual for the correct oil, or Special Publication, SEBU6250, "Caterpillar Machine Fluid Recommendations" for additional information.
Table 1
Sales Model Amount of Additive per Axle
Wheel Loaders
910E, 910F, 910G, 914G 0.47 L (0.5 qt)
924F, 924G, 924GZ 0.47 L (0.5 qt)
928F, 928G 0.47 L (0.5 qt)
936F, 938F, 938G, 938G II, 938H 0.47 L (0.5 qt)
950F, 950F-II, 950G, 950G II, 950H 0.47 L (0.5 qt)
960F, 962G, 962G II, 962H 0.47 L (0.5 qt)
966F, 966F II, 966G, 966G II, 966H 0.95 L (1.0