Hi, I am trying to change my back rotors and pads on a 1999 4wd blazer. I got the rotor off but I am having a really hard time compressing the pistons. I cannot get the new pads on. I bought a tool that checkers told me would work but it didn't, any ideas on how to compress the piston? I also tried a c-clamp but it wont budge, just messed up my clamp.

 

if you have the bleeders open and they are clear-you can blow thru them, then my guess is that you have set up calipers-could that possibly be part of the problem that you're going after? Later Jerry ps I guess it is possible to just compress the caliper piston but I personally clamp off the brake hose and compress the piston allowing the brake fluid compressed out the bleeder allowing none to go back thru the system. Just my personal preference on how I do it.

 

alot of those rear rotors take a weird spinning type tool that spins as it pushes it in. not sure if your truck has them if it has two little v notches on the caliper then you need that tool

 

on my 01 they just pushed in

 

I'd agree with the others, it sounds like your caliper is froze up. It should compress in quite easily and certainly shouldn't break a c-clamp.

That is on calipers with an integrated parking brake. The s-series rear disc setups have an internal drum for the parking brake. The rear calipers are just a simple piston design.

 

another idea. try doing what peru motors said. open the bleeder and then try pushing. then if it goes easily you might have a collapsed rubber brake hose

 

Good point. I had assumed that he already tried it with the bleeder open.

I always open the bleeder to push the piston back in. That pushes all of the junk that accumulates in the calipers out. You just have to remember to top off the reservoir before and after you are done to make sure that you do not introduce air into the system.

 

This happened to me, under a worse circumstance....just replaced the back caliper with a semi loaded one....Junk gets in there and stiffens and seizes up.....Me i was on the highway going through a city on about a 1600km trip..happened to hit rush our traffic...hit the brakes and BOOM. rear pad blew up from all the heat build up from the sticky piston.sounded like someone rear ended me. Got lodged between the rotor and the caliper..picked it out managed to drive to a part store and then princess auto to gets some parts and tools to fix it and get back on the road (and only using the tranny to brake was a challenge).tried to compress the rear piston and it was completly seized up...........calipers dont cost an arm and a leg if its sticking i would personally just replace it

 

haha. glad nothing serious happened, I had a similar problem when I first got the blazer, comming off the freeway I had the rear drivers brake lock up on me... luckily I was a few blocks from work, just took it slow and let the locker over power it....

IMO, Change it. When it comes to brakes, do it right. It's what stops your truck.


cracking the bleeder while pushing the piston in will drain the fluid out, like everyone else is saying. Another benefit to that is you get to put in fresh fluid. Brake fluid is designed to absorb x amount of condensation to prevent brake parts/line from rusting inside-out, which is why it is recommended to flush it every so often(although not very many people do). Easy to do while bleeding the brakes.

 

take the cap off your master cylinder to let pressure out of the system, then try.