Wompa164

iTrader: (4)

Hi everyone,

I've been spending the week taking care of refreshing my entire brake system. This also includes rebuilding all of the calipers. I was having difficulty removing the front pistons from the caliper so I enlisted the service of a local shop to get them loose for me. The owner of the shop really seemed to know his stuff, but the quality of the work leads me to believe otherwise.

They got all of the pistons loose (only two blew out using an air compressor), and he told me they used channel lock pliers to get the rest out.

The pistons look pretty trashed. My life and braking performance rides on the hydraulic sealing of these parts and I'm not willing to leave it up to chance, so I'm asking for the opinions of the professionals and the semi-professionals on here.

Are these re-usable, provided I give them a little spot and polish and smooth things out? My main concern is the scarring on the actual edge of the piston body itself, not so much the upper ring. Although I am concerned that the marring on the top of the ring will lead to premature dust boot failure.

zenofspeed

iTrader: (1)

I'd smooth them out and reuse them. They should continue to seal fine.

I'm not a professional, but I've rebuilt around 20 calipers on my various vehicles.

Mahjik

iTrader: (1)

They are usable, but I personally wouldn't reuse them. There are tools which can be used to get them out without tearing them up:

https://www.rx7club.com/suspension-wheels-tires-brakes-20/brake-caliper-piston-removal-333883/

billyboy

Looks like your guy moonlights as a butcher on occasion.

Rather than give an unqualified opinion - perhaps measure from the top of the bore to the top of the seal cutout and then measure the same distance from the bottom of the "step" to the lowest gouge in the hard chroming of the piston.

From memory, when fully retracted, the top of the working surface on the piston is level with the top of the bore.

My usual practice when disassembling calipers, is to place a piece of wood in the rotor cut-out (approx disc thickness), apply air, then use a slightly thinner section and repeat. Short of pistons being rusted into the caliper, you'll get even the sticky ones coming out evenly....and won't end up with a couple ricocheting off under the bench and the other ones fully seated!

GARCO MOTORWORKS

If they were mine and new ones are not to be found ,I would put them in the lathe and undercut the bad edge and turn some off the dust boot end .Then polish the rest . I have done some before on a Vet and for a motorcycle . I have had trouble getting one or two pistons out but never had to do as your guy did .I would never give anything back to a customer like that .

Gadd

New ones are available for about 20 bucks each from Mazda. Conversely, you could probably find some used calipers in the classifieds and steal the piston from them.

Paul

Wompa164

iTrader: (4)

Thanks for the advice everyone. I think I'm just going to turn them in as core and get some remans!