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Rebuilding Stock RS calipers

Hooskworks

Member
Joined
Apr 17, 2018
Messages
43
I'm about to do discs, pads, flexible lines and a fluid flush on my FD so i thought it might be a good time to rebuild all the calipers and paint them if it's not silly money to get the parts.

Is there a known good list of parts and part numbers laying around to do a full rebuilding of the RS / RZ calipers?

Any idea of where's good to order them (Amayama?) and cost would be really useful too.
 
Mazda do pretty complete rebuild kits. Or there are aftermarket ones available, but personally, I'd stick with oem.

Worth getting new slider pins and bleed nipples, they are quite cheap. You can get new pad hardware, depends on the condition yours are in, mine were fine so I reused them.

Project Mu used to make aftermarket pistons for the RS brakes, but they've since been discontinued.. You can get stainless pistons for the rear, I got some on eBay as the rears usually rust up pretty good.
 
Do Mazda do rebuild kits that include the pistons or is it unlikely that i need the pistons at all?

I found the following kits which include pistons and bleed valves on eBay from aftermarket suppliers but aftermarket parts for something like this make me uneasy.
https://www.ebay.co.uk/itm/for-MAZD...repair-seals-kit-Pistons-BRKP258/282972525862
https://www.ebay.co.uk/itm/Mazda-RX...iper-repair-kits-pistons-PK347-2/332871228439

Alternatively I tracked down the following Mazda OEM part numbers for the seal kits and the hardware
Mazda FDZ33329Z - ANTI-SHIM KIT
Mazda FDY12649Z - ANTI-SHIM KIT
Mazda FB0549240 - SEAL AND GASKET KIT
Mazda FDY12646Z - SEAL AND GASKET KIT

I'm still on the search for OEM slider pins and bleed valves.
 
Pistons should be fine. Also slider pins I wouldn't worry about replacing unless there's something definitely wrong with them, bleed valves I replaced mine with speed bleeders.

I rebuilt my R1 calipers using a Bigg Red kit, which was good although the dust covers were a bit of a funny size and needed coaxing in.
 
Pistons should be fine. Also slider pins I wouldn't worry about replacing unless there's something definitely wrong with them, bleed valves I replaced mine with speed bleeders.

I rebuilt my R1 calipers using a Bigg Red kit, which was good although the dust covers were a bit of a funny size and needed coaxing in.

Same here (not R1 just stock), I've got the rear kit too, just too lazy to do them. And as above all parts were good except seals etc.
 
Do Mazda do rebuild kits that include the pistons or is it unlikely that i need the pistons at all?

I found the following kits which include pistons and bleed valves on eBay from aftermarket suppliers but aftermarket parts for something like this make me uneasy.
https://www.ebay.co.uk/itm/for-MAZD...repair-seals-kit-Pistons-BRKP258/282972525862
https://www.ebay.co.uk/itm/Mazda-RX...iper-repair-kits-pistons-PK347-2/332871228439

Alternatively I tracked down the following Mazda OEM part numbers for the seal kits and the hardware
Mazda FDZ33329Z - ANTI-SHIM KIT
Mazda FDY12649Z - ANTI-SHIM KIT
Mazda FB0549240 - SEAL AND GASKET KIT
Mazda FDY12646Z - SEAL AND GASKET KIT

I'm still on the search for OEM slider pins and bleed valves.

That ebay link is for the smaller calipers, the pistons and seals are not the same. I'll dig out the part numbers for you tomorrow (y).
 
Front rebuild kit for RS/RZ/RS-R/SP/SR etc F1Z43326Z
Front slider pin (Need x4) F12433696
Front bleed nipple (Need x2) B00133691

The pistons are still available new for just under £15 each, probably cheaper to send them off in the uk and get some made if yours need replacing.

Rear caliper rebuild kit FDY12646Z
Rear bleed nipple (Need x2) 023333691
 
Last edited:
Thank you! You've saved me form myself again and It even comes out at a reasonable cost for everything too!

I'm assuming the rear caliper rebuild kit should be FDY12646Z so it takes the form of the rest of the part numbers? (and comes back as something)

1544003088761.png
 
I'm about to do discs, pads, flexible lines and a fluid flush on my FD so i thought it might be a good time to rebuild all the calipers and paint them if it's not silly money to get the parts.

Is there a known good list of parts and part numbers laying around to do a full rebuilding of the RS / RZ calipers?

Any idea of where's good to order them (Amayama?) and cost would be really useful too.
How will you go about repainting the calipers? Would you sand blast first, or is there a less invasive way? I've sand blasted a previous set, but the finish wasn't as smooth as I'd hoped.
 
I wouldn't blast them, unless soda. You can usually get away with a decent brake cleaner, scotch pad and good paint.

I like the VHT caliper paint. I went with their high temp white primer, caliper paint colour and caliper paint clear. Seems to hold up well and has a nice glossy ceramic look to it. Done 7 sets now.

37710315451_a82e4407da_c.jpg


37710320371_332a7da5d3_c.jpg


23857134688_cbfb0cd318_c.jpg


Wish Project Mu hadn't discontinued these pistons

13223222814_a51cb8ae1e_c.jpg


13223265224_f17404f58a_c.jpg
 
How will you go about repainting the calipers? Would you sand blast first, or is there a less invasive way? I've sand blasted a previous set, but the finish wasn't as smooth as I'd hoped.

As @Ceylon went for; I'd be looking at a good clean and de-grease and maybe brillo pad to shift surface oxidation then go to paint.

Mine are in pretty good condition already. M'm mostly looking to smarten them up whilst i've got them off to do a rebuild and i'm only rebuilding as i'm flushing the entire system to replace fluid, some lines, master cylinder fluid bottle, pads and discs. (see: scope creep)
 
Nice, I've done a few calipers mostly non FD and every time the piston needed replacing, calipers pins too. They just corrode.
 
Those last two pics are the ones now on your car Joe, those pistons won't rust being durillium alloy :cool:.

Yeah, I always replace the pins, it's a right pain when they get corroded up and stuck. Think I even chromed yours for added bling :D.
 
If new OEM pistons are expensive (and they always rust) are there any good leads on where to go for replacements / upgrades?
 
Front rebuild kit for RS/RZ/RS-R/SP/SR etc F1Z43326Z
Front slider pin (Need x4) F12433696
Front bleed nipple (Need x2) B00133691

The pistons are still available new for just under £15 each, probably cheaper to send them off in the uk and get some made if yours need replacing.

Rear caliper rebuild kit FDY12646Z
Rear bleed nipple (Need x2) 023333691

Massive legend (y)
 
Those last two pics are the ones now on your car Joe, those pistons won't rust being durillium alloy :cool:.

Yeah, I always replace the pins, it's a right pain when they get corroded up and stuck. Think I even chromed yours for added bling :D.

Phror nice, didn't realised they where special pistons! Unfortunately they not as pretty anymore :(
 
Does anyone have links or part numbers for new pistons for the bigger rs discs?

My rear calipers keep being a little sticky so planning on pulling them out and rebuilding soon. May also do the fronts while I’m at it so could do with potential front pistons too if anyone knows about them.

The rebuild kits number above are great, just don’t want to order parts and need other bits when I finally get round to sorting them.

Thanks
 
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