Sat 27 Sep 2008
Dan’s Garage
My friends, Dan and Dave, helped me rebuild the front brake caliper assemblies on my motorcycle today. The good news is that Dan really knows how to recondition brakes, and we got my 22 year old brake assemblies back into good condition. The bad news is that we never regained pressure in the brake lines, so these newly cleaned brakes don’t work. Good thing Dan lives nearby, because I drove home on just the rear brake. Something tells me the next step is rebuilding the master cylinder, but I’m hoping not.
January 20th, 2009 at 8:10 pm
Can you provide more on this?
January 20th, 2009 at 10:14 pm
Sure. I don’t think the brake fluid had been changed at all during the life of the bike. It was brown, indicating water absorption.
Also, the piston inside the brake caliper had corrosion (due to the water in the brake fluid) and would not slide smoothly in the caliper.
So we removed the old piston and cleaned out the brake caliper housing with a Dremel tool that had a metal brush attachment. This got the metal on the inside of the caliper assembly clean again.
I replaced the piston and seals with new parts, available online.
And I replaced the brake pads.
Since we needed to drain the brake lines to do this work, they were empty when we were done. At the time I did not understand that the master cylinder piston (as apposed to the brake caliper piston) would not pump enough fluid to refill the brake line in any reasonable amount of time. Instead it was necessary to use a pump to draw the brake fluid through the lines. I borrowed a brake fluid pump from a friend, and it worked great.
Once I learned more about what was going on in my situation I decided my 22 year old brake lines needed replacement as well. And while I was at it I decided to rebuild the master cylinder piston.
So I got all this stuff installed and rebuilt, and now my brakes work great. Except that they squeal. I am pretty sure it’s just brake dust, and I have not spent any more effort trying to quiet them. They work great otherwise.