Motorcycle Repair: Brake Fluid, dot 5 brake fluid, silicone brake fluid

Question
What is it about HD's that require DOT 5 brake fluid instead of DOT 4, or silicone based fluids that aren't rated? Very fast Street Rods with disc brakes, and fast Japan bikes use the above fluids with no problems. Is there something in the brake system that requires the DOT 5? The DOT 5 is usually only available at HD Dealers. Not good when you're touring, need brake fluid, and not near an HD shop.


Answer
SILICONE BRAKE FLUID HAS A HIGHER BOILING POINT AND DOES NOT ADSORBE WATER, IF YOU MIX SILICONE BASE BRAKE FLUID AND GLYCOAST BASE BRAKE FLUID LIKE DOT 3 OR DOT 4 YOU GET (GLUE)  NOT GOOD.  NAPA AUTO CARRIES DOT 5   
SOUTHSIDE JOHNNY 602-340-1266 PHOENIX AZ.
www.southsidesdyno.com