I'm putting brakes on my '00 Trail Boss, and decided to replace the pistons and rings on the calipers as well. The service manual says to coat the new piston with brake fluid, and push it into place. It also said that the piston should slide in and out with little resistance.

My piston is TIGHT. It will hardly move at all. I eventually had to put brake fluid back in the system and pump it out, just to get the piston out.

New piston, new rings, tighter n' a tick!. Why? What should I do?

Larry

 

Anybody have any ideas? I don't want the brakes to drag like they were, even when adjusted.

Larry

 

Ther isn't any rust or debris in the caliper is there? Also are you starting it straight?

 

Yes on both accounts. I might try starting it again, and pay more attention to how straight it is, but I don't think that's the problem.

I cleaned the caliper out carefully, using a Q-tip with brake fluid, so I know it is clean.

Larry

 

Do these calipers get hot enough to warp a little? Maybe my calipers are warped, and that's why I'm having a hard time getting the new piston in.

Larry

 

I checked the calipers by taking out the gaskets and putting new pistons in and seeing if they would spin easily. My theory is that if they are warped, even slightly, then a new, round piston wouldn't turn. Well, they turn perfectly, so I don't think the caliper is warped.

I know this isn't a high end, high-revving, screaming machine like most of the units here, but I need some help! I don't want the brakes to drag like they were, and I believe if I put it back together with these pistons this tight, then it won't function properly. Can't ANYBODY help me?

Larry

 

Have you tried honing your cylinders? If you had problems before, a simple parts change won't cure the cause of original failure. You wouldn't replace engine piston without addressing the bore, same goes for the brakes, or anything else that has and relies on close tolerences. hope you get it figured out, having your quad sidelined sucks! Good luck

 

First of all are you sure you go the right parts for your model? Second was the old piston hard to move in and out? I have put a lot of brakes on trucks and cars and it usually takes a C clamp to push the piston in. It could be 2 things caliper is bad or your brake line could be bad. Hope this helps.

 

How do I tell if the caliper is bad? What about the brake line?

I decided to put it all back together today, and see what happened. It all goes together fine, but once the brakes are bled and adjusted, only one squeeze of the brake handle causes the piston (and thus the brake pad) to stay pretty tight against the disc.

Ho hum...this is getting frustrating, but not as frustrating as paying a dealer to not get it right either.

Larry

 

My 95 scrammy was the same way. I had to drive it out from the rear. Inspected it and it seemed to be in good shape. I think the heat/ prolonged pressure might work on them over time.