Rear caliper piston will not retract

Black_Penguin · Postby **Black_Penguin** » Fri Mar 15, 2013 1:03 pm

No matter how much I wind the adjustment screw the passenger rear caliper piston will not retract.
Any ideas?

zero00 · Postby **zero00** » Fri Mar 15, 2013 1:09 pm

Black_Penguin wrote:No matter how much I wind the adjustment screw the passenger rear caliper piston will not retract.
Any ideas?

If you have been driving and get that smell of burning brakes, I had that and am told common on NB's - It loosened off after a few km's but I solved the problem with new rears

I stopped at the lights 15km from home after sitting on 100kph - thought someone had brakes cooking only to find next stop it was still there and the wheel centres were kinda hot!!

That's my 2 bobs worth!! [20 cents]

Black_Penguin · Postby **Black_Penguin** » Fri Mar 15, 2013 1:17 pm

Trying to replace pads, if I can't retract the piston I can't get the new pads over the disc.

Black_Penguin · Postby **Black_Penguin** » Fri Mar 15, 2013 3:30 pm

Pushed the piston back in with a G-clamp. All together now.

spikey · Postby **spikey** » Sat Mar 16, 2013 7:24 pm

There is a 14mm at the back of the caliper, take that off and it will reveal an allen key bolt, loosen that and it will retract.

Black_Penguin · Postby **Black_Penguin** » Sat Mar 16, 2013 8:28 pm

I was turning the allen key grub screw however the piston was not retracting. Application of a g-clamp fixed the issue.

de Bounce · Postby **de Bounce** » Sun Mar 17, 2013 8:22 am

Sounds like it has been butchered/broken previously!

aka_juffa · Postby **aka_juffa** » Sun Mar 17, 2013 11:02 am

Sounds like you have/had the 'in-famous' stuck slider pin. At the minimum you need to inspect the slider pins on both rear brakes. If they are in good condition then you have been lucky and all you should need to do is grease them with brake specific grease (high copper content I believe).

If the slider pin is in poor condition, such as pitted/rusty, and/or the brakes still won't retract with the grub screw then it maybe possible to clean up the slider pin, or replace it.

A 2nd hand rear caliper will set you back around $160.

More info here.

slider pin search results

spikey · Postby **spikey** » Sun Mar 17, 2013 7:44 pm

I have got some Na6 rear calipers if you want them? $120 delivered for the set.
Thanks
Terry

Black_Penguin · Postby **Black_Penguin** » Wed Mar 20, 2013 12:35 am

NA6 calipers will not work on my NB8A.

spikey · Postby **spikey** » Wed Mar 20, 2013 2:51 am

Try mx5plus, they should have them.

Purfler · Postby **Purfler** » Tue Nov 12, 2013 11:15 am

I know this is an old thread, but I thought I'd share my recent experience with a rear piston that would not retract. I was replacing pads and discs, the old pads were very worn. Could not get the passenger side to retract. Took off the caliper found the piston had rust which was stopping it being pulled back. As the pads were very worn the piston was out to its fullest extent. I have a suspicion the dust boot was not seated properly, but I was not paying close attention to it. I have ordered new pistons, seals and hoses for all 4 from MX5parts in the UK. (If I'm going to take them apart I might as well renew everything.

Tim

Lokiel · Postby **Lokiel** » Tue Nov 12, 2013 11:49 am

Greasing the caliper slider pins is something that should be done as a maintenance check at least once every 2 years, otherwise the caliper will not self-align correctly and you'll end up with only one pad doing the braking. If you look at your pads, massive uneven wear from one pad to the other will indicate if you have this issue.

On the SE/MSMs, some guys found that the pins weren't even greased at all so this appears to be a production line issue.

This should be one of the first maintenance checks you do when you buy an NA/NB.