Rear Brake caliper stripdown - help!!

[ChrisL 17]

First Ive managed to break the little plastic stopper for the handbrake lever, does anyone have a scrap caliper or can you buy these?

 

Also, how do you get the main seal out of the calipers please?

 

finally, does the handbrake lever on the caliper at the back come off please?

 

I want to strip the caliper down for shot blasting, painting etc.

[James. 7]

To remove the handbrake lever, you have to strip the caliper down internally. I left the lever in place and covered the hole where the piston sat with some 2mm plastic. Sandblasting wasn't a problem and the results came out really well. If you're careful, you can remove the piston seals without damaging them. Perhaps prudent to change them, but there's no harm in checking them over before they get consigned to the bin.

 

Not sure what you mean by plastic handbrake part but bentley would be my first port of call.

[ChrisL 17]

thanks James, hows best to remove the seal? it looks to have a metal ring inside.

 

On the back of my caliper where the handbrake lever is, there is another metal plate that is held on by a single socket screw. This plate has a plastic part that acts like a stopper for the lever.

 

Oh, and I got the piston out by pumping the handbrake lever, is this OK??

Edited February 17, 2013 by ChrisL

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Hello Chris, I've just attached a few pictures for your attention regarding the rear brakes.

 

Chris the rear brakes on the Corrado's are about the same as the MK2 Golf / Passat,

I think some of the later Corrado's may have the MK3 Golf brakes.

 

The rear caliper piston these normally unscrew outward when removing them,

you do this by using the caliper removing tool,

if you look at the outer head of the piston you will see two or four rounded slots,

well the caliper removing tool has some raised studs on the face of a disc,

and this disc fits over the front outer edge of the piston so you'll be able to remove or install the piston.

You can remove the piston by operating the handbrake lever but you should really use the caliper removal tool.

 

The rear brake caliper piston moves on a central shaft with a spiral like thread,

so if you don't have this tool it could be a bit of a swine to unscrew it.

You have to use this tool when ever you replace the rear brake pads, so as to adjust the piston.

Remember to use copper grease on the back plate on the pads and runners, and EP grease on the caliper guides.

 

The tool if you need one can be purchased off Ebay or Amazon for around £20.00

 

Unlike the front brakes these just have a piston that slides in & out and is very easy to remove & install.

 

THE DUST BOOT SEAL

All calipers have a dust boot seal that stop water, dirt, brake dust from entering in to the cylinder,

and getting between the piston & cylinder.

This dust boot fits in to a ridge in the outer edge of the caliper cylinder wall,

and is held in place by a circlip,

this circlip can be removed & installed by using a small flat headed long stem screw driver,

once the circlip is removed the dust boot seal will then come out, followed by the piston.

 

INNER SEAL

The inner piston seal you remove these by using a very small flat headed long stem screw driver,

these seals fit in to a ridge in the inner cylinder wall of the caliper,

but be very careful because if you scratch / scrape deeply in to the cylinder wall it can course a poor seal surface between the cylinder wall & the piston,

if this happens you can use fine sand paper to smooth the caliper cylinder wall,

but it only really works when the scratch is shallow if it's deep then it could be a git to smooth out.

 

Never reuse a piston if it's pitted badly around the lower to mid surface edges where it slides in the caliper,

as it may not seal and could be dangerous, :shocked!:

and the same goes for the calipers if the cylinder wall is badly pitted and won't smooth out using fine sand paper,

throw it out and get a replacement caliper, it's just not worth taking the risk :nurse:

 

Always use the correct brake piston caliper grease this is normally red or orange in colour,

this grease is silicone based & heat resistant plus keeps moisture out and helps to keep the inner seal in place.

 

NEVER USE EP grease which you use on bearings as this is too oily and piston won't slide as well.

 

Chris I believe you can remove the handbrake lever on the rear brake caliper,

but you need to get the overhaul kit that has all the new seals and bits with in that kit.

This can be a bit of a fiddly job.

 

Chris I'm not sure about the plastic stopper I don't think you can buy them separately.

 

 

I hope this helps, good luck mate :salute:

 

Cheers

 

Si :thumbleft:

[James. 7]

Yeah the piston will just keep going till it falls out. Same on the fronts as well. I usually pop the fronts out with an airline. I used a soft tipped pick to get the seal out. The crust and rust that builds up around them seems to help hold them in.

[ChrisL 17]

Yeah the piston will just keep going till it falls out. Same on the fronts as well. I usually pop the fronts out with an airline. I used a soft tipped pick to get the seal out. The crust and rust that builds up around them seems to help hold them in.

 

Thanks James, will have a try.

 

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Hello Chris, I've just attached a few pictures for your attention regarding the rear brakes.

 

Chris the rear brakes on the Corrado's are about the same as the MK2 Golf / Passat,

I think some of the later Corrado's may have the MK3 Golf brakes.

 

The rear caliper piston these normally unscrew outward when removing them,

you do this by using the caliper removing tool,

if you look at the outer head of the piston you will see two or four rounded slots,

well the caliper removing tool has some raised studs on the face of a disc,

and this disc fits over the front outer edge of the piston so you'll be able to remove or install the piston.

You can remove the piston by operating the handbrake lever but you should really use the caliper removal tool.

 

The rear brake caliper piston moves on a central shaft with a spiral like thread,

so if you don't have this tool it could be a bit of a swine to unscrew it.

You have to use this tool when ever you replace the rear brake pads, so as to adjust the piston.

Remember to use copper grease on the back plate on the pads and runners, and EP grease on the caliper guides.

 

The tool if you need one can be purchased off Ebay or Amazon for around £20.00

 

Unlike the front brakes these just have a piston that slides in & out and is very easy to remove & install.

 

THE DUST BOOT SEAL

All calipers have a dust boot seal that stop water, dirt, brake dust from entering in to the cylinder,

and getting between the piston & cylinder.

This dust boot fits in to a ridge in the outer edge of the caliper cylinder wall,

and is held in place by a circlip,

this circlip can be removed & installed by using a small flat headed long stem screw driver,

once the circlip is removed the dust boot seal will then come out, followed by the piston.

 

INNER SEAL

The inner piston seal you remove these by using a very small flat headed long stem screw driver,

these seals fit in to a ridge in the inner cylinder wall of the caliper,

but be very careful because if you scratch / scrape deeply in to the cylinder wall it can course a poor seal surface between the cylinder wall & the piston,

if this happens you can use fine sand paper to smooth the caliper cylinder wall,

but it only really works when the scratch is shallow if it's deep then it could be a git to smooth out.

 

Never reuse a piston if it's pitted badly around the lower to mid surface edges where it slides in the caliper,

as it may not seal and could be dangerous, :shocked!:

and the same goes for the calipers if the cylinder wall is badly pitted and won't smooth out using fine sand paper,

throw it out and get a replacement caliper, it's just not worth taking the risk :nurse:

 

Always use the correct brake piston caliper grease this is normally red or orange in colour,

this grease is silicone based & heat resistant plus keeps moisture out and helps to keep the inner seal in place.

 

NEVER USE EP grease which you use on bearings as this is too oily and piston won't slide as well.

 

Chris I believe you can remove the handbrake lever on the rear brake caliper,

but you need to get the overhaul kit that has all the new seals and bits with in that kit.

This can be a bit of a fiddly job.

 

Chris I'm not sure about the plastic stopper I don't think you can buy them separately.

 

 

I hope this helps, good luck mate :salute:

 

Cheers

 

Si :thumbleft:

 

Thanks Si but cant see any pictures.

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Right just tried it again.

[vw rule 19]

There you go mate these pictures show you most of the workings in the rear calipers.

 

Si

:thumbleft:

[ChrisL 17]

Great thanks

[vw rule 19]

No worries dude :D

 

Hope you get your brakes sorted :thumbleft:

[ChrisL 17]

Quick question!

 

I am going to rebuild my calipers now I have them all painted. The pistons dont need to be greased when I re-install them do they????? Is it just the 2 carrier spindles that are greased?

 

Thanks

[Jonathan Claxton 10]

And where the pads touch the carrier obviously, there should be no paint there just copper slip

 

A little bit of oil will help them slip in but no grease

[vw rule 19]

I normally use a little EP grease on the caliper sliders I find this works really well and yes you can use oil as well,

a part from on some of the Vauxhall's you do need then to use the correct silicone grease on those though,

as they can have a rubber ring on the centre or on the end of the slider shaft,

so if you use EP grease the sliders will be extremely tight as there is zero tolerance,

and if you use oil on some of these Vauxhall brake sliders then it may make the rubber rings swell,

which in time will course the sliders to seize up completely.

You can remove the rubber ring but then the caliper won't be sitting straight on the carrier,

as the sliders will be too lose as they will no longer have the rubber ring to align them.

You normally get new rubber rings as a kit when replacing the pads on some of the Vauxhall's, Citroens and Renault cars.

Remember that the silicone grease has a very low resistance drag so allows the slider to move freely in these zero tolerance sliders.

 

I find when I use oil on the sliders they tend to still rattle on some cars,

so that's why I use a very small bit of EP grease as it helps to take some of that play out,

plus will go slightly oily once the brakes are up to temp but not as thin like oil.

But as long as you don't use copper grease on the sliders,

as this grease has a very high melting temp limit and so is a lot thicker,

it will course the sliders to drag too much which will course uneven brake pad wear,

or even completely seize up.

 

As regards to your question I always regrease the caliper piston with silicone grease (for rubber seals),

so it'll slide nice and free plus there will be less chance of the inner seal catching and tearing.

Some people like to put the brake piston in dry but I always grease them up.

 

It's like an engine or gearbox you would never rebuild one bone dry,

you would oil every inner part and prime all the oil galleries that you could,

so the same aplies I believe to brakes when rebuilding them or door catch or hinge.

 

 

Si

[swampy 0]

I use brake grease from Ecp

Its made by pagid and only costs a few quid a tube but lasts really well