Dragging front brakes

Dragging front brakes: Normally this is caused by contamination in the calipers not allowing the pistons to retract. Normally a good cleaning will resolve the problem. BUT ,, here is another cause.

If the piston in the master cylinder or the bore is contaminated or possibly a weak return spring not pushing the master cylinder piston to its home position, the pressure your create when applying the brakes will not be relieved because the intake/relief hole is blocked by part of the master cylinder plunger piston seal. Therefore you front brakes or rear for that matter will drag. I removed my master cylinder and flushed the cylinder bore with brake cleaner in both the input and output sides. I was amazed at the crude that came out of the intake/relief hole.

Now my front brakes after cleaning the master cylinder bore and piston are working correctly. This was completed on my 1995 Yamaha 750 Virago, but I will clean the master cylinder on my 1999 RSV also.

Don’t forget about the master cylinder causing it to. Had my front wheel start locking up at 70 mph.

really smoking bad, then about 20mph, she locks up. Found debris in the master cylinder relief hole. Drilled it out bigger, cleaned it good. No ,ore problems.

If you have rubber lines they can cause issue also. The inside of the line rubber will deteriorate and it almost acts like a check valve. The fluid under pressure from master will go out to caliper, but does not have enough pressure on return to get by the fragments. I have not actually seen it on any bikes, but I have seen it on older cars front brakes primarily.