Brake Fluid Basics

Harley-Davidson motorcycles use either DOT 4, which is glycol-based, or DOT 5, which is silicone based.

Beginning in 1976, Harley-Davidson used DOT 5 in all its brake systems.

For model year 2005, the FL platform changed to DOT 4.

For 2006, all models except XL went to DOT 4.

For 2007, All models use DOT4.

When working with Any Brake Fluid follow these very important steps;

   1.  Cover the tank and fenders as an added measure to prevent any spilled brake fluid from coming in contact with paint.  Beware of any fluid dripping down the frame tubes.

   2.  Level the master cylinder BEFORE loosening the cover to prevent spills onto painted surfaces (glycol-based fluids damage paint).

   3.  Determine what type of fluid is currently in the system, it may have been changed from the factory specification.

   4.  If glycol-based brake fluid is spilled on paint, do not use a pressure hose to spray it off, as the paint will have softened.  Use soapy water, rinse thoroughly and let it air dry.

   5.  If you suspect that different types of brake fluids were mixed together in the system...you should completely rebuild it, using all new rubber parts, as contamination goes deep into the old parts.

These are just a few precautions you should take when working with brake fluids.  If you should have any other questions...Stop by the shop and we'll be happy to answer them for you.

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"RJL" 3/07