how to rebuild a atv brake calipers polaris

motodad224 · #1 (**permalink**) 04-12-2011, 02:22 PM

I recently bought an '05 trailblazer for my wife and when I was playing in the yard on it the other day, I grabbed the brake lever a little hard and it blew out the rear caliper seal. My question is how big of a pain is it to rebuild the rear caliper, or am I better off just buying a new caliper? Thanks in advance for any insight you guys have.

**Bruce!** · #2 (**permalink**) 04-12-2011, 04:09 PM

Welcome to the board!

7.62Addict · #3 (**permalink**) 04-12-2011, 07:12 PM

Calipers are very easy to rebuild. You just need a little compressed air and a small set of picks to remove the square cut orings. I have done mine on my 01 500. Because its a stepped piston for the backup brakes, there are two orings. The only time you should need to replace the housing is if your piston bore is all oxidized from not changing the fluid or scratched up from improper handling during the break down. It would be really obvioius it its bad. You use a little compressed air to remove the piston, pull out the old orings and install the new ones. Use fresh brake fluid for lube and reassemble and bleed the brakes.

700ryder · #4 (**permalink**) 04-13-2011, 05:18 AM

I too need to replace my caliper seal but when I was under the quad looking at it there seems to b some kind of star bit I will need..is that special.to a quad or is it just like an automotive bit

7.62Addict · #5 (**permalink**) 04-13-2011, 05:28 AM

Nothing special, just standard fasteners. You should be able to get any of them at Sears. Torx bits are quite common.

motodad224 · #6 (**permalink**) 04-13-2011, 07:46 AM

Yeah this one has a backup brake as well, how do you remove the piston w/ compressed air? Do I just shoot it in the hole that the hose connects to?

7.62Addict · #7 (**permalink**) 04-13-2011, 08:00 AM

you use a blow gun or air nozzle to push the piston out of the caliper piston bore. I would suggest removing the bleeder screw with a bleeder wrench or other six pt socket carefully as not to break it. Plug the brake hose hole with a finger or something and slowly apply air. Put your hand over the piston so it wont go flying across the room. It helps to drain out all the brake fluid first so you dont make a big mess. Brake fluid will remove paint and is just plain nasty stuff. I would suggest using Valvoline Synthetic brake fluid when you refill and bleed the system. Its just good stuff. Synthetic brake fluid is still hydroscopic so proper fluid flushes are still required to prevent heavy water contamination that can cause early brake line and caliper failure. DOT 3 and 4 brake fluid of all kinds absorbs moisture out of the air. Only DOT 5 which is not compatible is moisture proof.