Anyone ever rebuilt brake calipers?

[Justin & Muttley]

A while ago I bought some late bay calipers for my x-over (the originals are seized I think) but I took a closer look at them today and I recon they could do with new seals etc - is this a difficult job to do at home? Would I need to split the calipers or can it be done with them intact? Also, best place to get a kit from?

Any pointers gratefully received...

 

[Justin & Muttley]

Anyone?

 

[Loxy]

I rebuilt mine a while back, its pretty simple assuming that there isn't any corrosion in the piston bore.

Hardest bit was getting the pistons out, I just worked them out using bit of wood and a g clamp while still connected to the brake hose (you need to do a side at a time this way or all your brake fluid ends up on the floor :lol: ).
I have heard that you can use a grease gun to get them out if they aren't attached to the brake hoses but never tried this myself.

The actual cleanup & refit is pretty simple really. I've done a few thousand miles on them since & I haven't not stopped yet

EDIT: I did mine intact without splitting.

 

[Fortunate Son]

Yep, did mine (71 model year only ones but same process)

Got caliper rebuild kit from GSF (no body else seems to do them) which includes main seals that slot into caliper, dust seals and the 2 small (8mm ish outside Dia 3mm ish inside Dia) seals that go between the two caliper halves.

Someone advised me that its only worth rebuilding calipers if the pistons are not too badly pitted as its hard to get a good seal if they are. Mine were a bit pitted but I used very fine grit wet and dry to polish them up.

I used a foot pump to blow out the pistons but make sure you put something between the pistons to stop them smacking into each other and getting damaged when they shoot out (I used a thin piece of timber).

Once pistons are out, split caliper, remove old seals and clean up.

The bit I found the hardest was getting hold of some red rubber grease (which is essential to make sure the pistons dont skew and sieze with dry seals, which DOES happen - that was on my beetle - smoke from both front wheels - pillock that I am thought I would "test" how hot the discs were with my fingertips, as you do - Oh dear I said,.... or words to that effect! - my fingers still have flat ends to this day!!) Finally got some from my local (then) old school independant motor factors - Minifords in Crewe - small sachets- 50p each.

Its a fiddly job but a lot cheaper than recon / new calipers.

Hope this helps and good luck with it

Give me a shout if I can help further

Cheers

Andy

 

[muntz70]

excerpt from ratwell.com

http://www.ratwell.com/technical/BrakeJob.html" onclick="window.open(this.href);return false;

I do not recommend you split the caliper to replace the o-rings to completely replace all seals: leave that alone. See Bentley for all the caliper rebuilding instructions. Use brake fluid for lubricating everything during assembly. VW says use brake paste but it's not readily available anymore even from over the counter at the VW dealer. You may also use brake rubber grease from PBR which is castor oil based.

 

[Justin & Muttley]

Thanks guys, I'm pretty sure I'm going to give it a go (I've got a spare pair of calipers after all!!!), I won't split them if I can help it.

Time to order a rebuild kit...

 

[Loxy]

Sure my rebuild kit came with rubber grease, got mine from JK IIRC and they fitted my crossover calipers fine.

 

[cyberdyne systems]

Hi check out my thread:

http://forum.earlybay.com/viewtopic.php?f=2&t=10062&start=20

You need to be able to push them out if they are seized, so use an air line for that, otherwise its pretty easy to clean up , use rubber grease (can be obtained from a motor cycle shop) and fit the new seals.

Gareth

 

[Justin & Muttley]

When I Googled it earlier the pages I checked all said to use brake fluid )rather than rubber grease) - is this a viable alternative?

 

[Marvel]

I refurbed mine last summer as I was getting a bit of binding. So when I inspected them properly the dust seals were absolutely buggered and so were the pads. This meant that one of the pistons was so far out of position it wouldn't return. I removed both calipers, pistons and split them as well. I also used very fine wet 'n' dry on the pistons as they were a little pitted, and used the refurb kit from GSF. I also got a couple of the little sachets of grease from them thrown in. Once back together I tarted them up a bit with caliper paint and they haven't let me down yet!

 

[Justin & Muttley]

Bit of an update, I've been out to the garage and taken a close look at the early and late calipers side by side and the early (stamped with 71) calipers are in much better nick - under the dirt and dust they still have the original gold paint!). I've removed the pistons and seals from one early caliper without incident and the pistons are remarkably good with just a light polish required - hopefully the caliper on the other side will be as good.

Looks like it's staying 'one year only' after all!!

 

[Araon]

If they are pitted its no real deal splitting the halves and having the cylinders honed either yourself or whip em to your local workshop will only cost a few quid and the old school guys will whip in and have them done in a couple of mins whilst your having a cuppa

 

[Justin & Muttley]

The main problem with my later calipers is that the top of the pistons (where the dust seal attaches) are quite corroded and would need to be replaced.

 

[stuif]

This is what i did, I had to split them because only one side caliper came out :evil:
Pushing calipers out

Then split and put rubber in between instead of o-ring, bold back together and again push the other side (outside) out

And put it all back together with new seals and rubbers

Hope this will help a bit

 

[Guest]

if you split the calipers its very important you don't reuse the bolts holding them together. you shuld be using brand new replacements.