Help! Are these caliper pistons rebuildable?
03-15-08, 02:11 PM
#1
Help! Are these caliper pistons rebuildable?
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. Also, if you don't have any experience with brake work, please don't make extraneous comments if you're not sure.
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. Also, if you don't have any experience with brake work, please don't make extraneous comments if you're not sure.
03-15-08, 04:11 PM
#2
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It looks like they did a real number on your brake caliper pistons. My first concern would be some of the clamp marks and scratches that stretch out over the O.D. of the piston.
It is crucial that the groove seal does not make contact with these imperfections. Any damage to the seal will cause reduced braking performance, affecting retraction and knockback resistance as well. (It appears the only time at which the imperfections on the piston could possibly make contact with the seal is during the reinstall of brake pads???)
Polishing the pistons should also be avoided as well. In my experience pistons are typically coated or treated. I'm unsure what Mazda has done in this case. However removing any type of surface treatment to the pistons could cause corrosion and could affect piston retraction. This could also decrease the life of the groove seal.
In short I would not reuse them.....that is only my opinion.
It is crucial that the groove seal does not make contact with these imperfections. Any damage to the seal will cause reduced braking performance, affecting retraction and knockback resistance as well. (It appears the only time at which the imperfections on the piston could possibly make contact with the seal is during the reinstall of brake pads???)
Polishing the pistons should also be avoided as well. In my experience pistons are typically coated or treated. I'm unsure what Mazda has done in this case. However removing any type of surface treatment to the pistons could cause corrosion and could affect piston retraction. This could also decrease the life of the groove seal.
In short I would not reuse them.....that is only my opinion.
03-15-08, 04:47 PM
#3
Please don't cross-post messages:
https://www.rx7club.com/suspension-wheels-tires-brakes-20/help-these-caliper-pistons-trashed-rebuilding-calipers-739082/#post7981523
https://www.rx7club.com/suspension-wheels-tires-brakes-20/help-these-caliper-pistons-trashed-rebuilding-calipers-739082/#post7981523
