Front brakes not releasing

[hopalong_neil]

Ok guys, just finished fitting my race spec inlet manifold and been test driving the car but having an issue with the front brakes, running an st202 conversion.

Both are dragging badly creating hot wheels and burning brakes.

I've checked out both sides and they are sliding on the pins ok but the pistons on both sides seem overly hard to compress. I checked both sides by compressing the piston a little, spinning the wheel which was nice and free, then applying the brakes and trying again. Both sides I struggled to turn the wheels after trying the brakes.

Granted the car sat around a little while whilst sorting the inlet but before i remove and strip calipers i was wondering if there's anything else that might cause this given both front are affected.

The rears are perfectly fine and release after using brakes or handbrake, only the fronts seem to have a problem.

Thanks in advance

[4e_FTe]

Hi bud, i had this before on a diff car and it turned out to be the calipers them selves and it was both of them at the same time like your having, everything was free on them even pushing pistons back, sliders free etc, tried 2 new ones and it was sorted.

[ryan lang]

the pistons have a 'spring back' seal that stretches under compression and then retracts when the brakes are let off.

if these are old they will eventually lose their retraction meaning the pistons wont make their own way back.

[hopalong_neil]

Thanks for the replies.

Stripped the brakes down yesterday and turns out it was corrosion in the caliper in the lip of the bore just before you reach the seal. Looks like the rubbers weren't doing a good job of keeping the moisture out.

Cleaned up and working fine for the moment but suspect that I'll need new calipers at some point as the surface is pretty pitted.

[ryan lang]

yeah get yourself a rebuild a kit which comes with a piston, and get it all sorted.

either that or upgrade ;)

[hopalong_neil]

Well after a longer test drive ive discovered that one of the seals is leaking 🙁

Given this and the caliper bores were pretty rusty it looks like time for new brakes...

Anyone know if there any direct replacements for single pot st202 calipers? Seem to be struggling finding the single pot units, only twin pots that I have found.