Brake Piston Won't go back enough when changing Pads/rotors

[wau5]

Having troubles pushing the piston back in enough when changing front discs & pads.
Heavy duty C clamp does nothing, using leverage and old brake pads in also does nothing much , seems like it doesn't simply wants to go in any further.

I don't have the special tool to push the piston back in, but I have changed the pads on this car previously many years ago without any much problems so I would think I have enough force.

Any ideas what can you do? Yes, I have removed the brake fluid container cap before doing it.

I read somewhere when researching randomly perhaps you need to open the bleeder valve as well not only the container cap, or that would make no difference?

the car is 22years old & When Looking upclose I can obviously see there is some rust.
Not really sure If I'm just not pushing hard enough,not doing something correctly  or there's something wrong with the callipers/pistons and perhaps they need service/new seals or replaced all together.

Attached some pics, any ideas would be highly appreciated!
Thanks.

[madasafish]

new caliper time..

[kevinivtec]

hello
22yrs old?  I would not even bother get a new calliper and start from scratch make life easier for yourself new pads, and top up with new  brake fluid looks like brake fluid has attracted water as it does and rusted it out i would not even bother to buy  a new seal kit either just get a new calliper for both sides my advice

[Beanbag]

As above, do the lot change both calipers on that axle and also the fluid , you cannot muck around with brakes your life depends on them.
Given the state of the pics, check all the calipers front and rear to be on the safe side.
Afraid these are the things to expect on a car that age , ours is 18 years old on 82K one careful owner and things still crop up.
Good luck and happy safe motoring.

[Westy36]

Yeah, I'd go with new caliper. You could try gently filing the rust off and see how it goes? Nothing to lose. A beefy c-clamp will put enough force on it though.

I bought a cheapo caliper wind back tool off ebay a few years ago for £10 ish. It's worked on every car I've tried it on and came with a whole selection of different fitment bits. Worth buying for the few quid they cost imho. If you live nearby, welcome to borrow it. 

[c.lday44]

Yeah, I'd go with new caliper. You could try gently filing the rust off and see how it goes? Nothing to lose. A beefy c-clamp will put enough force on it though.

I bought a cheapo caliper wind back tool off ebay a few years ago for £10 ish. It's worked on every car I've tried it on and came with a whole selection of different fitment bits. Worth buying for the few quid they cost imho. If you live nearby, welcome to borrow it. 

I too have the cheapo ebay special brake windback tool kit, works a treat, my calipers went straight back in.

[Westy36]

Yeah, they are brilliant devices. Just checked, and I bought my tool from Ebay seller Lin Feng 10/2020 for £13.99. Same kit today is £14.99 eBay item number:264839448878. Loads on there, so you may well find cheaper. 

[wau5]

Thanks for the Info,  ordered a set of new calipers.
29 euros / £24 a piece ain't that bad. Didn't wanted to faff around with the Repair Kits at that price.

[wau5]

Thanks for the Info,  ordered a set of new calipers.
29 euros / £24 a piece ain't that bad. Didn't wanted to faff around with the Repair Kits at that price.

[embee]

FWIW,  I always use a small paintbrush to apply "red rubber grease " around the piston and seal area whenever I am in that area in order to reduce the likelihood of corrosion.  It isn't a 100% guarantee to prevent it completely but it makes a big difference.
Use ONLY  red rubber grease,  ordinary lithium type petroleum based grease will attack the rubber used in brake seals. A 500g tin will probably last you a lifetime, costs single figure pounds if you shop around.
It also stops the seal sticking to the piston in those cases where you need to rotate the piston to wind it back in, I've seen too many split torn dust seals from people just rotating the piston. Just brush some RRG into the groove under the dust seals.

[madasafish]

I use WD40 - works a treat. Does not affect rubber.

[embee]

Brake system seals are usually EPDM, you can look it up..
WD40 is essentially a mixture of white spirit type solvent and mineral oil plus some waxes, you can easily check the safety data sheets online.
EPDM is not compatible with these substances,  you can easily check the rubber compatibility charts online.
I would recommend not using WD40 on brake seals,  but check for yourself.

[fashionphotography]

most likely seized pistons but can always try and undo the bleed nipple then try pushing back just in the event there could be a collapsed brake hose

[degzi]

Even with a wind back tool they can be really hard to wind in.

Expect them to need replacing again in a few years. Really should have drums at the back end.

[madasafish]

My 2012 Jazz has its original calipers which work perfectly .. services every three years..