Some rear disk brake calipers require the piston to be rotated to get them retracted. I believe it is to do with the hand brake operation. If there has been no mention, in the Haynes or YouTube videos, about the need for a windback tool then I would think it doesn’t need one. I normally use a small clamp to help push the pistons back, very little pressure required just easier than pushing by hand

Wind back direction for the piston is typically reversed from side to side on the car – so ideally you need 2 variants of wind back tool, or fiddle about a lot on one side.  Often easier if you crack open the bleed nipple on the calliper too – this also avoids back-flushing seal wear debris into the ABS unit (which can lead to very big bills).

I can never remember which way to turn the pistons on my wife’s car – have to use trial and error each time.  At a push you can do it with a pair of long nosed pliers, but the wind bank tool does help.

If the handbrake cable connects to the callipers, the piston will need turning to wind the internal ratchet back down the threaded shaft.  If the car has separate brake drum/shoes for handbrake, then no need for winding back – just push.

Wind back pistons will have a slot.

On 28 October 2024 at 15:12 Nicholas Farr Said:

Hi John Hill, I had to do that job on my last Astra that I had, it’s not just a matter of winding them back, as you have to apply some pressure to it at the same time as rotating it, there is a tool for the job, but I think they were quite expensive when I looked, so I just used a G clamp, and a pair of water pump pliers, although it was a slow process.

 

They’re so cheap it’s not worth improvising – LINK

I bought a very similar set for <£20 over ten years ago, and it works better than just a G-clamp to push back plain pistons.