Are brake caliper pistons still available?

[tw2]

I took my brakes apart yesterday and the pistons are not in the best shape. There is surface corrosion and scratches which will possibly affect the internal seal. I did find some available in the UK. I haven't gotten the vernier calipers out yet to confirm the dimensions. Just wanted to check if anyone knows of any in NZ?

https://brakeparts.co.uk/shop/TOYOTA/MR ... rs/BCP1586

[mknz]

Supercheap auto can get them surprisingly. Also, post pictures and we can tell you what's fine and what's not

[GDII]

Some of the USA supplied seal kits come with new pistons and I'm pretty sure the fronts are 36mm diameter but best check first.

[tw2]

Thanks guys. I don't think any piston damage above the level of the inner seal will be a problem but my vice grips broke and I caused the gouge with the red arrow which will affect the contact surface. They are $87 from Toyota. I don't want to replace things unnecessarily but I don't see the corrosion getting any better and the UK price of NZ$27 isn't too terrible. I haven't pulled the other ones apart yet.

I also can't decide whether to paint the calipers and rotors with high temp paint. Or what colour but it would be pretty low key.

[mknz]

Yeah getting mine out was a fight. For the UK price I would just buy new ones since your current ones would probably chew the seal

[tw2]

Yeah getting mine out was a fight. For the UK price I would just buy new ones since your current ones would probably chew the seal

I think it might be a good investment for the future. There was quite a lot of crap under the dust seal of the back one I checked too. I haven't got the piston out yet but it is hard to turn even with the useless cube tool.

Do you remember if the supercheap price was any better? I can't imagine they would have stock in NZ, probably comes from Australia anyway.

[GDII]

The rear ones just crank the handbrake lever on the caliper until they come out.

[mknz]

The rear ones just crank the handbrake lever on the caliper until they come out.

I tried this, mine had to be unscrewed with giant polygrips

[85AW20v]

If the pistons are getting hard to remove, reattach the caliper and use the brake pedal to pump the pistons out.

[mknz]

If the pistons are getting hard to remove, reattach the caliper and use the brake pedal to pump the pistons out.

You can do this, but keep the MC topped up and clamp each hose for the calipers already removed

[tw2]

I bought all new pistons from the UK shop. The measurements were identical to the one on my desk. I found some excellent videos on rebuilding them, the best one was for an MX-5, the caliper was single piston but seemed pretty much the same design otherwise. No way I would ever want to touch an 8 piston caliper for rebuild!

I bought a couple of wire wheels and some "aluminium" coloured caliper paint, hopefully will make them look acceptable.

[tw2]

Just an update. For anyone pulling the brakes apart I found I could remove the pistons with no damage by levering against the lip with a large screw driver and various sized sockets. I didn't do any damage this way even with the vice grips to remove them in the end as they were already so loose. Of course if I did it again I wouldn't do this at all. I am pretty confident if you remove the rotors only but leave the brake pads and pump the brakes the pistons will come almost all the way out on all four calipers before you disconnect the brake lines. The other tip I found watching youtube video's is if you want to use compressed air you can cut the rubber brake hoses in half to shove an air compressor fitting inside, of course only if you are replacing them with stainless lines.

I know a lot of people use a screw driver and hammer to get these seals out. That worked for the back but the fronts were so set in place they weren't moving. In the end I slipped the vice grips in where the metal of the base of the seal formed a lip over the edge and wrenched it out. After a few of those I could hammer a screw driver underneath to finally pry it out. Very stubborn.

[tw2]

Next thing was the painting. I wanted a subtle colour but between all four repco and supercheap stores in Hamilton "aluminium" colour was the only one available in VTH caliper paint except if I wanted red or yellow of course. I cut up an old car wash sponge to fill all the bolt and piston holes. This worked really well.

My next problem is that I don't have a dremel to clean up this surface rust. I will take them down to my local brake shop and see if they will do it for me and reassemble the calipers (I could do this but they do it all day every day so might as well, the dust seals look very difficult to install)

[tw2]

Question- does anyone know why these front pins only have one rubber seal between the two of them? Does it matter which one has the seal (top or bottom)? I presume it is just to give a little friction to smooth out the slide mechanism.

Next question- does anyone know how to remove the "stuff" from inside the rear pistons? From what I have read the new pistons don't have this spring and retainer installed.

Final thing I wanted to suggest is that if anyone wants or needs to rebuild their calipers I would approach it with caution. At this age a lot of calipers will have much worse damage than mine and there is a high chance they are not rebuildable. I would set out at least a few weeks to have your car off the road. I would suggest pulling the calipers apart before ordering a single thing. If the brake seal cavity is rusted out then they are rubbish. If you need to buy a couple of brake tools, all new pistons, seal kits, rotors, pads, lines and want to clean them up then you are a huge portion of the way to buying a brand new big brake kit.

I don't think anyone is selling the original wolfkatz full replacement kit anymore with wilwood handbrake calipers for the back. If you have a 92+ (I think) with good back calipers then you can use the mr2 heaven BBK which relocates the rear brake caliper out to use RX8 rotors, new wilwoods on the front with supra rotors and new lines. I don't think any of these kits will be suitable for 89-91 cars. Also look at MR2Ben and http://www.brakeparts.co.uk for new OEM calipers which will also take all the hassle out of it.

I think I got lucky with mine. In my opinion even the earlier OEM brakes are perfectly adequate for anything but track work. With a refresh, decent pads and new rotors they should never need upgrading. Hopefully one of the vendors will re-develop the full front/rear with hand brake wilwood kit for those with non-rebuildable brakes. Edit- I forgot about https://wilhelmraceworks.com/wilwood-big-brakes

[GDII]

Did you paint the rotor faces with that VHT?