Caliper piston won't wind in

[RR76]

I've open the reservoir cap and setup up the rewind tool. I managed, with a fair bit of force, tpo wind the piston in a couple of turns but now it seems firmly stuck with around an inch still out.

Any ideas?

[colin_p]

Usually backing off the tool a touch and then continuing gets over this problem. Repeat as neccessary.

The issue is that the rewind tool doesn't exactly match the thread pitch in the caliper and they bind up.

[Megaflow]

What car? Fiats have been known to have LH threads. I found this out by double checking Google before I went medieval with a 3’ breaker bar... close call!

[GreenV8S]

RR76 said:

now it seems firmly stuck with around an inch still out.

Sure you haven't been winding it out?

[RR76]

colin_p said:

Usually backing off the tool a touch and then continuing gets over this problem. Repeat as neccessary.

The issue is that the rewind tool doesn't exactly match the thread pitch in the caliper and they bind up.

Would opening the bleed valve make a difference?

[colin_p]

RR76 said:

colin_p said:

Usually backing off the tool a touch and then continuing gets over this problem. Repeat as neccessary.

The issue is that the rewind tool doesn't exactly match the thread pitch in the caliper and they bind up.

Would opening the bleed valve make a difference?

Don't know, what car is it and what does the workshop manual recommend?

[RR76]

colin_p said:

Don't know, what car is it and what does the workshop manual recommend?

Well the Haynes just say use a tool to rewind the piston, that's it, it give no details, waste of money, other than that there is no detailed info. It's a Skoda Octavia 2010.

[bluezedd]

as it sounds like you can move it a bit, I'd cycle through winding it in and pumping it out with the brake (not too much) and see how you get on

This is assuming you haven't reached the maximum already.

pump it back out. I might consider lifting the dust boot too and cleaning that area, but be warned that some cars can be a pain to reseat them.

[Drive it fix it repeat]

Some cars have an Allen bolt on the back of the calliper to wind in the piston. I found this out after using all of my available force and leverage on a mk2 mx5 caliper. How nothing broke I have no idea, whoops.

[Chris32345]

Press the brake a bit to push it back out then try to rewind some.more

[Drive it fix it repeat]

What area do you live OP? May be someone local who can give you a hand.

[RR76]

It seems the O seal needs replaced in the caliper, what would cause them to deform?

[Evoluzione]

Some idiot who doesn't know what he's doing maybe?

[Dave.]

Evoluzione said:

Some idiot who doesn't know what he's doing maybe?

Harsh

[RR76]

Evoluzione said:

Some idiot who doesn't know what he's doing maybe?

It's called a learning process.

So the piston screws in fine with the O seal removed, the piston, bore and grooves have all now been cleaned but still won't wind in with seal Installed so I'm wondering why a seal would cause this, it all looks fine but maybe it's out of dimensions.

I lubed it with brake fluid but maybe it just needs a new seals, it this a possibility, do seals warp?

[RR76]

Zulu 10 said:

They generally don't warp, but they can expand and swell if exposed to fluids that act as solvents on them.

Hint: if you really must rebuild the caliper yourself then try these people: http://biggred.co.uk/ who alternatively will also refurb your caliper for a sensible price.

I appreciate your seriousness and professionalism but it's not needing rebuilt, it's a problem at the seal/piston interface. The rest of the caliper is fine. I know your meant to use red rubber grease and I have ordered a tin so I'll see if that fixes it.

You guys should have known the answer to this at the beginning that is was likely at the seal where the problem was.

It either needs a new seal or the correct grease. It's not rocket science.

[The Road Crew]

RR76 said:

You guys should have known the answer to this at the beginning that is was likely at the seal where the problem was.

It either needs a new seal or the correct grease. It's not rocket science.

So it's everyone else's fault but not yours?! Classic.

Youd be better off posting pictures when you post. Much easier to visualise what's going on/going wrong.

If you cant get the seal in after lubing it with brake fluid then trying again with red rubber grease won't make any difference. Something else is going on.

[Desiderata]

It's not a rear brake is it? With an electronic parking brake? On VAG ones you can't wind them back manually, you need to do it electronically via the OBD2 port.

[geeks]

Take your car to a garage before you hurt yourself or even worse, someone else, brakes are a simple job but if you cant even work out how to rotate a wheel then you shouldn't be even thinking about attempting this.

Calling others out for a job you don't even have the first fking clue how to do yourself is childish at best.

Looking at your posting history it is quite clear you should be anywhere near a set of spanners without adult supervision!

[rustednut]

RR76 said:

I appreciate your seriousness and professionalism but it's not needing rebuilt, it's a problem at the seal/piston interface. The rest of the caliper is fine. I know your meant to use red rubber grease and I have ordered a tin so I'll see if that fixes it.

You guys should have known the answer to this at the beginning that is was likely at the seal where the problem was.

It either needs a new seal or the correct grease. It's not rocket science.

I was going to reply to this, with some more information that might help.

But I am out.