Has anyone rebuilt one of the front brake calipers? How hard is it?

You can buy a caliper rebuild kit for about $40.

New caliper costs $420, used caliper costs $170.


I've had one front caliper fail (piston siezed up) and the other one will probably go eventually so I'd like to rebuild it if it isn't too hard to do.

Wow, what timing lol.


I just, this weekend took on this endeavor. Something to think about, if you had one fail chances are the 2nd isn’t far behind. In my case, living in Germany for a year wreaked havoc on everything on the car (mainly the extreme amounts of salt used on the roads). The outside of the caliper piston had the surface marred with pits from salt/debris. Anyway, here is what I ended up needing...

Old Caliper
Brake Cleaner, In my case I used 2 bottles of the stuff, one on each caliper... love it
Caliper Rebuild Kit (Kits have parts to rebuild 2 front OR 2 back)
Steel Wool
Something to cover your brake lines with ( I used sandwich bags and rubber bands)
DOT3 or DOT4** brake fluid (DOT3 is stock, I use DOT4**, higher boiling point)
Air Compressor, ya air compressor.
Brake disassembly/reassembly Instructions and Bleeding Procedure


You can download the Mazda Instructions @ http://atomixcomputers.net/misc/Rx8/Disc.pdf

Removal is pretty strait forward, once you get the brake line off make sure you cover it (sandwich bag and rubber band or twist tie works well) and then you can shove it up near the top of your strut (so fluid doesn’t leak out).

You can see from the diagram on page 18, only 2 bolts (#2) need to be removed for the caliper to come off.

With the Caliper off use compressed air where the brake line connected to force the piston out of the caliper

***NOTE*** USE SHORT CONTROLED BURTS OF AIR, PISTON CAN SHOOT OUT AND CAUSE SERIOUS INJURY IF YOU DONT PAY ATTENTION

ya I shot it out pretty fast

When you get the piston out pay VERY CLOSE ATTENTION to how the seals are coming off. Now inspect the piston and the caliper very carefully, if the shiny surface of the piston (below the lip) is pitted/rusted at all, you need to replace the piston. If the inside of the caliper is pitted rusted at all, you need to replace the caliper (cant rebuild)

Use steel wool to remove any rust around the lip of the piston and around the lip of the caliper.

Seals... this was the biggest pain in the ass I’ve ever endured. If you’re doing this yourself be sure to only do one at a time (so you can refer to the other while rebuilding.

After reseating the piston, reinstall calipers (making sure the bleeder port is on the top, ya I put em on upside down and wondered why I couldn’t bleed the brakes, HEY it’s easy to do, don’t judge me! lol)

Hook the brake lines back up, bleed brakes and done yay


If for some reason you do need to replace the whole caliper... I found that O'Reilly's/Checkers/Schuck's/Kragen and Murray's have a contract with a company called Cardone. They are the only ones that I know of that rebuild OEM Rx8 Calipers
and they are $90 for the FRONT and $160 for the REAR.

**NOTE** As of this post they did not have any in stock which means you bring your calipers to one of the above stores and they send them to CarDone and you get your rebuilt/cleaned parts back

Hope this helps.
Matt

Thanks for the detailed write-up.

Does the caliper rebuild kit come with pistons? I may need to replace mine.

This weekend I installed a used caliper to replace the one that seized up. Kind of a PIA but glad to have the car back on the road.

Nope..just the seals and dust boots

Aye, you will actually be stunned with you see what $40 buys you lol.. but hey... gotta pay to play right?

included in the Rebuild Kit...

2x Bleeder Valve cover boots
2x Caliper to Wheel Boots (and supplied greese to fill them with)
2x Internal Piston Seals
2x Piston boots


thats it, all rubber.... weighs less than 4oz


I did end up replacing my whole caliper because of the pistons, bought a set of used ones off ebay (was impatient) for 90$ shipped. Then I rebuilt those and installed. You prolly can buy new pistons.. .but the way mazda charges Id hate to see what those go for.