Caliper Problems

[bigmak]

I tried to replace my rear brake pads today and I had a really hard time trying to get the outboard piston to move back to make room for the new pad. It seemed to be stuck? The inboard piston moves like butter, and I had no problem getting the new pad in there. Does anyone know how to fix this? Could I have a bad piston/seal on the outboard?

Also, I noticed that BOTH of my bleeders on the rear piston leak fluid. Not much, but just enough to notice. I wrenched them down pretty darn tight, and I'm still getting leakage. Do these things have gaskets or o'rings on them that can go bad?

 

[maxcruiser]

I tried to replace my rear brake pads today and I had a really hard time trying to get the outboard piston to move back to make room for the new pad. It seemed to be stuck? The inboard piston moves like butter, and I had no problem getting the new pad in there. Does anyone know how to fix this? Could I have a bad piston/seal on the outboard?

Also, I noticed that BOTH of my bleeders on the rear piston leak fluid. Not much, but just enough to notice. I wrenched them down pretty darn tight, and I'm still getting leakage. Do these things have gaskets or o'rings on them that can go bad?

Bigmak, it sounds like it's time for a caliper rebuild. Were the two brake pads worn the same, or one more than the other?

Mike

 

[maleko89]

+1, time to remove the pistons and clean them up at least. Might as well do rebuild kit to replace little o-rings.

I think there are o-rings on the bleeders.

 

[bigmak]

The inboard brake pad was worn quite a bit more than the outboard. I woudl assume that would be because the inboard piston was moving as designed, while the outboard was stuck.

To my knoweldge, the calipers have never been rebuilt, and I haven't given it a thoughough cleaning since I've had it. I'll call the parts shop tomorrow and see about getting a rebuild kit. I'm sure it's overdue, especially with these problems.

 

[one2dmax]

Usually no kit is needed. Either use compressed air to pop the pistons out (watch out for spraying fluid) or use the fluid pressure itself. Polish up the piston and clean out the bore and re-assemble.

Sean

 

[bigmak]

I looked at the rear caliper schematic, and it doesn't show an o'ring for the bleeders? Should I just replace the bleeders since they are leaking, or is there another way to handle this?

 

[maleko89]

BigMak, I may be wrong. Try removing and cleaning the threads and then using thread sealing tape.

 

[one2dmax]

The threads don't seal. There is far more hydralic pressure then they could handle. Look at the tapered surface inside under the bleeder. Likely there is a small particle under it causing the leak. Removed the bleeded completely and clean both it and the hole very well. You should be able to re-install and be good to go. You don't need a lot of torque either.

Sean Morley

 

[bigmak]

Thanks for the tips! My repair kit should be here tomorrow, we'll see how that works too.

 

[bigmak]

Installed the new seal kit today. The old seals actually still looked good, but no use in taking a chance. I got the new seals in, cleaned everything up and put it all back together. Bleeded the brakes, and took it for a test drive. Now it's worse than before!! LOL!! I applies enough pressure to lock up the brake (usually) and it barely creeps to a hault. I sprayed everthing down really well with parts cleaner, so I don't think I got fluid on the pads or rotor. Now, I'm trying to figure out what I did wrong. Nothing is leaking, yet.

 

[Buster Hymen]

Installed the new seal kit today. The old seals actually still looked good, but no use in taking a chance. I got the new seals in, cleaned everything up and put it all back together. Bleeded the brakes, and took it for a test drive. Now it's worse than before!! LOL!! I applies enough pressure to lock up the brake (usually) and it barely creeps to a hault. I sprayed everthing down really well with parts cleaner, so I don't think I got fluid on the pads or rotor. Now, I'm trying to figure out what I did wrong. Nothing is leaking, yet.

It sounds like the brakes aren't fully bled.

 

[bigmak]

You got it Buster! That WAS the problem. I went back in last night and re-bled the brakes (emptied the resivoir twice) and got a few more air bubbles out of there. Works so much better now. Can even lock up the rear tire, not that I should be doing that anyway, but I wanted to make sure that I've got full grip! Thanks!