Resetting pistons to restore handbrake (after brake pad change)

[auzzam]

Hi guys,

So I changed my pads about a year ago... And didn't reset the rear pistons with the 180 degree step.

For the last year I've had no handbrake but thought its time I sort this out. I wanted to ask how the 180 degree step would work now because obviously the pads are worn. So winding the piston all the way back will mean it won't be in contact with the pad now.


Should I only wind the piston so far back that it just misses the pads, then rotate it 180 degrees back out?

Or do I need new pads again?

[mr2garageswindon]

Firstly check the handbrake levers on the calipers are back on their stops, if not the handbrake will be crap.
I'd be inclined to loosen off the handbrake cable till its slack, undo bottom 12mm bolt, swing caliper up and turn the piston all the way back in. Check that the sliders are nice and free on the calipers. Swing caliper back down, insert and tighten 12mm bolt.
Get in car and pump pedal until goes hard.
Then go and do the same to the other side, doing one at a time you are less likely to overflow the resevoir.
When pedal is pumped after you do the second side, re check the levers on calipers still on their stop then adjust handbrake to spec which is written by the adjuster. 5 to 7 clicks I think.
With the handbrake off the levers on the calipers must be on the stops.
Seized handbrake cable wont help.
New pads not needed.

[jimGTS]

the only winding the piston does is to screw in to fit new/thicker pads.

the piston still works the same in operation as the fronts, ie it pushes outwards when braking (it doesnt wind out).

i would always wind in far as you can go, then back out 180, pump on brakes, then good to go.

[SonicSW20]

The backout 180 degree step is not necessary, it's not mentioned in the workshop manuals.

Slacken and disconnect the handbrake cables first, wind the piston in fully (you should feel a change in resistance when they are fully in), ensure that the notch in the piston is aligned to 90 degrees, refit the caliper and pump the brakes hard so that the pistons are applying good even pressure to the pads on both sides. Reconnect the handbrake cables and set tension accordingly.

[jimGTS]

yeh cant say ive done the 180 thing for a while, i dont usually do it.
i thought it WAS in the bgb and people said not to bother (hence mentioned it).

if it isnt, then why the myth about it has spread round is anyones guess.

ive tried with and without, no difference.

[SonicSW20]

Same. I seem to remember there is a logic to the 180 degree thing but I've not noticed any difference as long as the rest of it is done properly.

Forgot to add to my post, make sure the notch on the piston is aligned correctly, added that in.

[auzzam]

Thanks guys will give this a go over the weekend, how would I know if I need new calipers?

The car brakes fine, but when previously rewinding the pistons the driver side rear caliper was tough to wind in. Since then I've changed the handbrake cables too.

So I'll give the above suggestions a go, but failing that I'm guessing caliper change?


I actually saw a post on here about the 180 thing and people swore by it, good to know it works without it

[raptor95GTS]

yeah Paul Woods spoke about the 180 degree turn. With the number of MR2's he's worked on I can't imagine him doing something he doesn't need to so if he says to do it then there must be a good reason for it.