piston wind back

[Simply Si]

after i recover from my hospital visits im planning on winding back my passenger side rear calliper and installing my new discs and pads, but, i need to know in which direction i need to turn it to wind it back.

i have an adaptor (made by draper) that is a caliper wind back key and you attach it to any ratchet bar and turn (i hope its the right thing).

so, as if i am looking at the piston face on, do i turn clockwise or anti clockwise or shall i just try both?

(oh and do i need the engine to be running when i do this or not)?

many thanks, si

[welshone]

I thought you just pushed back the piston doesn't need to be clockwise or anti and with engine not running :icecream:

[garythesnail]

As Ian says - the front brakes, just push back in (I used a quik-clamp and a bit of stick to make it quicker) - no need to turn / rotate.

If you're on about the rear calipers - you need to wind them clockwise. I've used a 2 1/2" wide masonry chisel / bolster, bit of left-over steel (don't ask) and a file succesfully in the past, so a 'special tool' isn't really needed, but I dare say it may make the job easier for you.

I've always done this type of work without the engine running.

Let us know how you get on.

[Simply Si]

thats awesome info. many thanks.

[welshone]

Don't forget to open the Brake fluid reservoir, will make it alot easier and put a rag around the opening just incase it overflows when pushing/winding the piston back.

[Simply Si]

Don't forget to open the Brake fluid reservoir, will make it alot easier and put a rag around the opening just incase it overflows when pushing/winding the piston back.

i was told i didnt need to touch the fluid at all. do i need to top it up after wards and will it need bleeding?

[welshone]

you shouldn't need to but you should remove the reservoir cap becasue your putting pressure on the piston this will make the fluid level to rise and might even spill over.

[Simply Si]

if i did this though, wouldnt the level stay above max once i put the cap back on, and also wouldnt there be air in the system?

[garythesnail]

Not an unfair question.

If fluid is at 'max' level now, once pistons are wound / pushed back in, there's less fluid in the caliper . . . . . which has to go back to the reservoir - so above the max level.

If you put the old pads back in (so no change in thickness), the piston will end up in the same position and the fluid level in the reservoir will go back down to the 'max' level.

If you put new (thicker) pads in - the piston will not 'stick out' as far (it can't because there's a greater thickness of pad there), so some of the 'surplus' brake fluid will stay in the reservoir rather than go back in the caliper - so level will be above the 'max' as you suggest, but it will be marginal.

As long as the pistons stay in place and the reservoir doesn't empty, you won't get ait in the system unless there's a separate problem with the system.

[welshone]

Once you've finished sorting the brakes out the level will drop a little again once the piston comes back out against the pads

[Simply Si]

hahahaaa, know it all!!! lmao

cheers ian and gaz. i just get paranoid where brakes is concerned as one false move and you have one big problem.

[Fast Alan]

I have a wind back tool called a big screwdriver used sideways,occasionally you get someone that has topped up the fluid not realising its gone down as the pads have worn,if you end up with to much fluid after fitting your pads,use the large syringe you just stole from the hospital

[Simply Si]

I have a wind back tool called a big screwdriver used sideways,occasionally you get someone that has topped up the fluid not realising its gone down as the pads have worn,if you end up with to much fluid after fitting your pads,use the large syringe you just stole from the hospital

umm, i think the advice before was abit more sound!:wacko:

[Fast Alan]

umm, i think the advice before was abit more sound!:wacko:

Its true though Ive pushed more pads back in than youve had hot dinners mate I only did it for 20 years and always took the top of the reservoir and rapped some rag around it,in case of spillage,though I doubt very much your going to get that,the syringe I joke about but if you did end up with a overfull reservoir how are you going to get the excess fluid out

[Simply Si]

20 years is a long time to change a set of pads lmao!

[Fast Alan]

20 years is a long time to change a set of pads lmao!

thats why Iam Fast Alan

[Fast Alan]

thats why Iam Fast Alan

Haha I looked at my last autodata book the other day and it was 1990-1994

[Simply Si]

would it make it easier to remove the brake pads and disc and then bolt the caliper back in place whilst i wind it in?

[Fast Alan]

would it make it easier to remove the brake pads and disc and then bolt the caliper back in place whilst i wind it in?

they seem to wind back in quite easily on the 200 and you have a zippy new tool so only for the sake of not being akward

[spankyban]

They aren't too bad to rewind (anti clockwise iirc)

Just pop the lid off the reservouir and you wont be pushing against a pressurised system.

Some skinned knuckles though!