Binding Rear Caliper?

[chris1712]

Hey guys, over the last week or so I've noticed a weird noise from the wheels. Kind of sounds like paper being pulled out of an envelope, it started off intermittent and I thought it might be a warped disc but today its more of a constant sheeting noise. Anyway when I got home, i had a quick glance at the discs and lo and behold my back drivers side was roasty hot, actually burnt my finger on it .

Am I right in thinking its a binding caliper? Or more likely a completely fudged disc? I was planning on changing to mtecs all round after April anyway (Uni hand in!) so Is there a way I can stave off this problem for a while? Or am I going to have to replace the caliper? They certainly don't look cheap!

I'm not a huge car DIY guy but I'm happy to learn and have a go, so if anyone has some good ideas/tutorials etc. on anything useful that would be great. Or are there any handy Bristol/Swindon area members?

Cheers, Chris

[rallyfan1986]

Probably just the slider pins that have siezed, mine have done it a few times now.

about £30 for a new set from toyota, or you could have a go at cleaning and regreasing the ones in the calipers already

[chris1712]

Probably just the slider pins that have siezed, mine have done it a few times now.

about £30 for a new set from toyota, or you could have a go at cleaning and regreasing the ones in the calipers already

Are they easy enough to replace? Any way I can tell whether its the pins or the whole caliper beforehand?

[rallyfan1986]

Yeh not difficult at all to check.

Take the back wheel off, behind the calliper there should be 2 bolts (12mm from memory)

Undo these, this lets you remove the carrier that holds the brake pads.

Once the carrier is out of the way, there should be two pins, that the removed bolts went into. They should have a little rubber boot on them.

You should be able to push them in with very little resistance.

If they don't move they are seized.

They pull out to replace them, you may need quite a lot of force to pull them out if they are seized.

Hope this helps

[chris1712]

Yeh not difficult at all to check.

Take the back wheel off, behind the calliper there should be 2 bolts (12mm from memory)

Undo these, this lets you remove the carrier that holds the brake pads.

Once the carrier is out of the way, there should be two pins, that the removed bolts went into. They should have a little rubber boot on them.

You should be able to push them in with very little resistance.

If they don't move they are seized.

They pull out to replace them, you may need quite a lot of force to pull them out if they are seized.

Hope this helps

Thanks for the help. Hopefully I can have a look at em before I head into Uni tomorrow. Do you know if the parts from toyota is like a refurb kit, with grease and replacement rubbers etc.? Or literally just the pins?

[rallyfan1986]

its the full kit.

ive only changed the fronts on mine, but i would guess you would get the same in the rear kit.

if it is the pins that have seized, as a temporary fix, you could pull the pins out and clean and grease them and replace them. although make sure the rubber boot is seated properly - I had to run a small screw driver round the recess in the calliper where the boot sits to clean out all the crap so it would fit back in properly

[chris1712]

OK I had a look today, and indeed one of the pins was a lot tougher to move than the other. They both moved, but not having checked something like that before I wasn't sure if they had too much/too little resistance.

The whole caliper is rusted to hell though, it was almost rusted to the pads for gods sake!

I'm not overly familiar with calipers, but it seemed to me like the whole thing wasn't being pulled away from the pads enough. Is it the springyness of the pin seatings that do this? Or is it just a case of the hydraulics remove the pressure on the piston which hopefully removes the pressure from the whole assembly? It looks to me like the piston would always be making slight contact especially on the rear pad.

Anyway it can't hurt replacing the pins, so I'll try that first. Just wish all this lasted another 3 months to when I've finished Uni, just don't have the time or money for this atm :censor:.

I've ordered a set from Toyota £47! Just for one corner aswell, rip off for two !Removed! pins and some bits of rubber.

[msprince]

Believe it or not but its the rubber boot that surrounds the caliper piston, that pulls the piston back to stop it binding on.

When your replacing the slides check to see if you can push the piston back into caliper, it should slide back in without using massive force, if it doesnt turn your piston could be sticking.

[rallyfan1986]

£47 seems a bit steep, my front ones were only £30 for both sides! Just dont put too much grease on the new ones or it stops the pin going all the way into its housing

its hard to explain how much force is required, but on one of mine you could push it in with your finger, the other needed a set of pliers to make it move.

they should return out on their own once you've pressed them in, not really fast, but they should spring themselves out.

If the piston is stuck, i wouldnt have thought the brake would work at all and the disc itself would be covered in rush.

the pads do sit very close to the disc, you could probably fit a sheet of paper in the gap

[chris1712]

Believe it or not but its the rubber boot that surrounds the caliper piston, that pulls the piston back to stop it binding on.

When your replacing the slides check to see if you can push the piston back into caliper, it should slide back in without using massive force, if it doesnt turn your piston could be sticking.

Yeah no chance. When I had it off today I pushed the piston back in but it a lot of force and a C clamp to do so. I just assumed that was because of the hydraulic pressure the other side :/. Damn, the calipers don't look cheap.

£47 seems a bit steep, my front ones were only £30 for both sides! Just dont put too much grease on the new ones or it stops the pin going all the way into its housing

its hard to explain how much force is required, but on one of mine you could push it in with your finger, the other needed a set of pliers to make it move.

they should return out on their own once you've pressed them in, not really fast, but they should spring themselves out.

If the piston is stuck, i wouldnt have thought the brake would work at all and the disc itself would be covered in rush.

the pads do sit very close to the disc, you could probably fit a sheet of paper in the gap

Thats straight from Toyota, a quick google found no other uk suppliers tbh. From what prince has said, It seems the caliper could be fubar, but certainly one of the pins was tougher to move than the other so might aswell change those aswell.

Pain in the ***** cars, this is the last thing I need when I've got the stress of final year Uni coming to a close, if only it could of survived one more month!

[rallyfan1986]

I don't think it will be the piston that's stuck (although I could be wrong)

When I had to push my piston in to change the pads I wedged a screw driver between the calliper and the piston and applied a fairly high constant pressure to the end of the screw driver, it took quite a lot of force to get it back in as there's a lot of fluid to push.

Can you jack the car up and get someone to turn the problem wheel while you apply pressure to the brake pedal? this will show if the brake is actually working or not.

If it comes to it you may need to strip the calliper down, give it a good clean and change the seals, this will be a much cheaper option than buying a new calliper, although will take a fair amount of time

[mr-p]

wire brush + copper slip for the pins, also when your pushing the caliper back in crack off the bleed nipple or undo the brake fluid resovior, you will have too bleed the brakes agian but it will help, as for the caliper take it off the car soak it in brake cleaner, pull back the rubbers and get some in there too, if you can get it in a kero bath/ parts washer

[chris1712]

I don't think it will be the piston that's stuck (although I could be wrong)

When I had to push my piston in to change the pads I wedged a screw driver between the calliper and the piston and applied a fairly high constant pressure to the end of the screw driver, it took quite a lot of force to get it back in as there's a lot of fluid to push.

Can you jack the car up and get someone to turn the problem wheel while you apply pressure to the brake pedal? this will show if the brake is actually working or not.

If it comes to it you may need to strip the calliper down, give it a good clean and change the seals, this will be a much cheaper option than buying a new calliper, although will take a fair amount of time

The brake is definitely working, but its not 'un' working :P. Ie not releasing all the pressure from the pads, whether its the caliper not withdrawing or the pins not doing their job I can't really tell :/

[CorollaD4D]

i have a sticky front pin on my car my mechanic discovered this while changing my front discs and pads he regreased them and put them back in again but i am planning on getting a slider kit and having him sort it out properly.

for your problem it sounds like the piston is fine, they usually need a lot of force with a screwdriver or a clamp to push back in. undo the brake fluid reservoir cap under the hood before you start work, this should make it easier just remember to bleed when your done.

and as for how much effort the slider needs on the side which was working correctly the lightest dab with one finger could push the sliders in and out whereas the one which was seized wouldn't move at all.

[mr-p]

ndo the brake fluid reservoir cap under the hood before you start work, this should make it easier just remember to bleed when your done

no need if your just undoing the cap only if you break into the braking system

[FoxX]

Ouch £47 ! I only paid £30 as well from Toyota at Queensferry and that was steep enough for 4 pins and 4 rubbers + a tiny pack of grease thats worth about 20p.

I had an issue where I couldnt actually remove one of the pins, actually got it in a vise in the end to remove it and on inspection - the rubber which comes on one of the pins was totally mangled. So cleaned it all out and popped in the new greased pin and is was working smoothly again.

But yes worth inspecting before purchasing, they are fairly robust - its just the rubber that keeps the rust out is not! Nrgizerbunny did a caliper strip down guide should you find its your piston thats sticking, although getting a stuck piston out would require a lot of wd40 :)

[CorollaD4D]

ndo the brake fluid reservoir cap under the hood before you start work, this should make it easier just remember to bleed when your done

no need if your just undoing the cap only if you break into the braking system

thanks for clearing that up. my mechanic makes me pump the peddle before i leave the workshop i had assumed that bleeds it maybe it just makes the peddle hard so i don't drive straight into something lol

[mr-p]

yeah its because he has pushed the piston back in, its so you dont crash the first time you need to brake

[KPARRIS-JONES]

I have haunting memories of winding my rear callipers pistons in....

The rear calliper pistons have a wind in mechanism as well as just pushing it, so they will be tough if all you're doing is pushing and not twisting. However it shouldn't be ludicrously tough.

I hope that you can get this sorted relatively cheaply, I know what it's like to have to deal with ball aches such as these... all too well.

KP

[chris1712]

Changed the sliders over just now, no good :(. Still sticking, though it doesnt seem quite so bad. Unfortunately I couldn't get the carrier off with my ickle tools so couldn't really clear out the holes, but they seemed pretty smooth.

Could it be a problem with the hydraulics themselves? IE needs bleeding/changing? The brake fluid is due a change anyway but it would cause a problem like this?

[chris1712]

Gonna order me some M-Tec rears and replace them anyway, am I blind or did they not used to sell pad+disc combos for the rear?

Are the other many drilled/grooved packs on eBay infact mtec discs aswell? How quick is their delivery, need em by Wednesday!

Also, rear discs. 279mm? ECP list two different sizes.

[chris1712]

Weekend bump!