Brake Fluid Change Intervals

Brake fluid-as with engine oil or antifreeze-eventually becomes contaminated with moisture and dirt. Depending on the type of contamination, the fluid may look dark, and the boiling point will drop.

Brake fluid should be changed at each major brake repair. Mineral or petroleum-based substances (gasoline, carbon tetrachloride, paint thinner, diesel fuel, etc.) attack the rubber compounds used in brake systems. Soft or swollen rubber parts in the hydraulic system indicate that the brake fluid is contaminated. Often the first sign is brake drag or lock, occurring when the swollen rubber parts prevent brake release. The only remedy is to drain the fluid, flush the system, clean the cylinders, replace all rubber parts including brake hoses, and refill the system with clean brake fluid.

NOTE: Rubber parts should only be cleaned in isopropyl (denatured) alcohol or brake fluid. If metal parts are degreased or washed in any solvent, rinse them thoroughly with alcohol or brake fluid to remove all traces of solvent residue. Always use clean containers for brake fluid and make sure stored fluid is tightly capped.