hi-

i've searched vendor websites and the archives and i'd appreciate any advice you guys have on a problem i'm having. i'm about to rebuild rear brakes and need a source for caliper pistons. i've looked on all the sites and cant find anything for the rear except advanced auto parts. the parts made by raybestos (yuck) and it costs $71 per piston. they are joking right? does anyone have a source for rear turbo caliper pistons or am i going to have to chase down a custom brake shop or machine shop to get this stuff?

also, please dont ask why i need them, i do. please also dont respond by telling em to just get rebuilt calipers. if you feel the need to respond in this manner, please dont respond.


thanks guys,
db

 

Bump

I also am wondering about this. O'Reilly's also has the pistons listed on their site but no price. I will call tomorrow and see how much they are.

My problem is this: The threaded part in the piston is able to spin when attempting to turn the piston so it retracts back into the caliper. Would it be ok to put a small tack weld to hold it in place while I retract it? I honestly wasnt thinking that a brake piston would be so expensive. Anyone else have any ideas/suggestions?

Thanks

 

Called O'Reilly's and they say that the piston is NLA. A rebuilt caliper is 70.99 so I guess I could save a dollar and just buy it, take out the piston and return it along with bad piston for the core.

Is the threaded part of the piston supposed to turn one way? Just trying to see if I actually need to buy a caliper or piston. Having a hell of a time getting the piston in. Didnt want to tear the other one apart again to check and see if it spins one way. When I turned the "good" piston to reinstall it went right in. The "bad" one does not. It starts and then just spins and doesnt retract down in like the "good" one did.

 

dont mind me asking but the difference between a turbo2 and a n/a one?

 

As far as how they work I dont think anything. In fact the FB GSLSE rear calipers work the same. As far as simple difference, the NA is considered a single piston and T2 is considered a 2 piston.

Edit: I am thinking that the screw should turn. If it didnt, the piston would turn while being pushed out which wouldnt work since the tabs on the brake pads would inhibit much movement.

Edit 2: Sooo, I guess Im mainly having problems installing the piston. It doesnt screw in like it should. It seems that because it is so tight against the new piston seal it is not letting it go in very easily. Calipers rebuilt because they were powdercoated.

 

the threaded stud remains stationary in the caliper body and the piston screws onto the stud...the studs are hard to strip and the piston sometimes take a little patience to get started. most of the time the piston will not fail..so i'm curious why the original poster is in need of new caliper pistons.

as a note, the piston will turn in past the seal. a little greasr does the trick. if you ordered teh rebuild kit from mazda, they give you three different types of grease to use. each is for a different section of the caliper or seals. did you properly install the stopper plate?

 

What?
The only difference between NA and Turbo rear calipers is the body width (to accommodate the wider, vented rotor)- the rebuild kits are identical.
Why then would the Turbo be considered a two piston caliper?

 

if the user that originally started this thread is worried about rebuilding the calipers due to brakes sticking...

do not forget to rebuild the e brake part of the caliper...

needle bearing, grommet, and clean the return spring...

 

To the OP:

If you haven't rebuilt any brake caliper before and/or cannot diagnose the problem with your current calipers, it is alot easier to just replace the old ones with a set of remans. They are not too expensive and is the most surefire way to eliminate any problems.

And the last time I checked, Mazda doesn't sell the pistons by themselves. IIRC, one of the aftermarket companies that sells OEM replacement parts might have them but I haven't had experience with that...

 

Thats what I have always heard. I never really understood why. Sorry to pass on incorrect information. Why are there 2 bleeders? I figured thats why people said that they were "dual piston"...

 

As far as I know. I didnt order the kit form Mazda though so no grease.

 

there are two bleeders for different caliper orientation on different cars i think

 

From what Ive read, you are supposed to bleed one first then the other (bleeder screws).

 

I've always just bled through the highest bleed port.

I think the "different orientation" theory explains the two bleeder locations the best.

 

What other car are they for? Why would they need to be oriented differently?

 

i dont htink they are manufactured to fit another mazda vehicle...

 

It's unlikely that they were manufactured specifically for Mazda in the first place.
Typically, a carmaker just picks these components from the brake manufacturers catalog as commissioning a model specific part- especially for a low volume production run like the RX series- would be prohibitively expensive.

These generic parts are frequently designed to be used in both RH and LH applications, so the body casting will have provisions- in this case, the bleed screws- suitable for either orientation.

Clearly, I have no inside info regarding the design process for the RX but this explanation makes more sense to me than some engineer specifically requiring two bleed screws- the lower of which would be practically useless for air removal.

 

In, my opinion, the rear calipers are ****. Clever design to save on weight and stuff, but that doesn't mean its good. On 2 remans I got, from 2 different companies, both had worn out pins inside that actuate the e-brake part. Apparently those don't get replaced. The whole thought of incorporating the e-brake into the caliper just pisses me off. With that, sometime in the future I plan on getting a 2 piston caliper and a separate e brake caliper.

Edit: Maybe FD3S rear calipers were designed slightly different to fix the e-brake mechanism. That might be an option as well.

 

any pics of a fd rear disc brake caliper next to a fc

 

I figured out what was wrong finally. Come to find out, the o-ring for the cylinder was what seemed to be the next size up. This meant that the piston was being pushed against the edge of the o-ring and not sliding past it like it was supposed to. I ordered another rebuild kit so tomorrow I will be able to try it out. I dont have any pics but it seems that if the o-ring that was included was supposed to be metric, the one I got was standard and the next size up.

I'll let you guys know what happens tomorrow. Thanks for the help.