On my SP 500 the brakes quit. If i would squeez the hand lever the foot would stop it. I just thought the pads were worn out (which they were) so i replaced them. Now when i squeez the hand lever the brakes still dont work and if i keep squeezing it, it will pump the fluid to the master cylinder of the foot brake and overflow the resivoir. Is there some sort of anti reverse flow valve in the caliper. I cant seem to find one.
Please help me out here

 

There should be a hex-head set screw on the back of the caliper. It's next to a rubber boot cover about 1/4" diameter. I just did my pads, I turned that set screw till my pads just started rubbing the rotor, then backed it off a quarter turn. Sounds like that might be your problem.

 

Quadfather, That adjustment screw only exists on the front calipers, not on the back - correct??

The rear brake caliper is a dual caliper. It has an inside piston and an outside piston. One piston is used when the hand lever is pulled. The other piston is used when the foot pedal is pressed. They are completely separate hydraulic systems.

The hand lever (ignoring the front brake circuits) has a resevoir at the lever. The lever forces fluid down the line to the rear caliper and the piston assigned to the hand lever (can't remember if it is the inside or the outside piston).

The foot pedal has its own resevoir under the seat. Press the pedal and the master for the pedal forces fluid down the lines to the other piston in the rear caliper. Note that on pre-'98 models the foot pedal was a cable brake system - not hydraulic.

If pulling the hand lever forces the fluid in the pedal resevoir (the other system) to overflow, then the rear caliper is not sealed correctly. The caliper is somehow allowing fluid to flow from the hand lever area of the caliper to the foot pedal area of the caliper. Time to crack the rear caliper open and rebuild it with the appropriate seal kit. This is the only possible way that fluid from the hand lever system can get forced into the foot pedal system. They should be isolated systems.

Good luck,

DJ

 

Thom
Both systems force both pistons out. Next time you have the caliper off experiment by pulling the hand lever or foot pedal. There is a channel that connects the 2 inside the caliper. The pistons may be froze and the path of least resistance is up the foot pedal hose to the reservoir.

98 SC 500