Brake Caliper Rebuild

[swedishandgerman]

If anyone is mad enough to rebuild your own front brake calipers instead of spending the £97 on a reconditioned one, here's how:

This is quite something: on a 3 pot caliper, the inside piston seizes up with age. Even so, they still seem to give sufficient pressure to pass an MOT even on the 2 little pistons. So even if you think your brakes are in tip-top, it's still worth checking things out

My old car had been standing for a few months, so when it went in for its MOT recently, it failed on brakes binding. I thought about levering things, but on closer inspection, the rubber components were brittle and the pistons were exposed looking very rusty

After taking the wheel off, I took the pads out. This is so simple - there are 2 guide pins held in with little locking clips. Once removed the pads can be lifted out, measured, inspected and cleaned up.

Taking the calipers off involves undoing 2 bolts that include a locking tab. Also disconnecting the brake pipe. I soaked these overnight in oil and I was lucky that they came off with little effort and didn't distort the pipe. Don't over force your spanner on these as they easy shear.



Next, you need to extract the old pistons. Apparently, you should use an airline, but I don't have one and seeing as these pistons were scrap, I put the whole caliper in a vice and levered them out with a grip. They were tight, but came out eventually.

Nasty looking! The corrosion build up is what makes the pistons jam up. Normally, they should float in and out on the rubber and not come into contact with the caliper body.



All the old rubber needs to come out.



I am lucky; I work for a shot blast manufacturer, so my calipers extraordinarily found their way into one of my customer's machines.



After, I sprayed them in a high temp silver paint.



A complete recon kit is available form Brookhouse including 3 pistons, 2 dust covers, 3 seals and a new bleed screw

Fitting in the seals was easy. Fitting the dust covers was fiddly. Putting in the pistons was more than fiddly.

1. Put the seals into the grooves,
2. Put the dust covers into position making sure they enter the grooves in the cylinders
3. Stretch the dust covers and with your imaginary second pair of hands - if you're lucky enough to have some - put the pistons into the cylinders, make sure the dust covers enter the piston grooves and fully inset them. This is a frustrating little job!

Now it's ready to go on the car making sure you remember the safety tab behind the 2 bolts. Reconnect the pipe, re-insert the pads, pins and locking clips.

Bleed the system and surprise yourself by how bad the brakes were before!

[222s]

Originally Posted by swedishandgerman

If anyone is mad enough to rebuild your own front brake calipers instead of spending the £97 on a reconditioned one, here's how:

This is quite something: on a 3 pot caliper, the inside piston seizes up with age. Even so, they still seem to give sufficient pressure to pass an MOT even on the 2 little pistons. So even if you think your brakes are in tip-top, it's still worth checking things out

Agreed. I had exactly that with mine the other year. Passed the MOT fine, but one of the dust seals was a bit manky, so the caliper was taken off to change the seal, and it turned out that the big piston was stuck... Didn't even bother looking at the other - just ordered a recon pair immediately from Simon. Those arrived the following morning, despite being ordered at about 16:30. The MOT tester couldn't believe it, when he was shown the offending item, as the braking performance was all properly balanced etc on the rollers. Also, I had only recently before then had to do an emergency stop at motorway speeds and it pulled up fine. However, once the new units were on, the difference was immediately noticeable.

[LMJ]

Changing the brake fluid every 2. year will keep your brake calipers last longer, as brake fluid by time, sucks moisture and get the pistons to rust and size. I wonder why the pistons not are made of stainless material.

[northNH]

They are available in stainless...

[tdz840]

Good review Adam, thanks!
Did you consider breaking the calliper in two halves?
I've seen arguments for both.
Where are the stainless pistons available from?
Russ

[Derek UK]

Originally Posted by northNH

They are available in stainless...

There is a Jag E type specialist in New York who has the little and large pistons available. Not cheap and unfortunately I can't find the link. Similar ones might be available from Jag spares companies here in the UK but I'd think a Volvo specialist somewhere would also have them.
An opportunity for someone in a machine shop somewhere perhaps?

[tdz840]

Of course Jag e types use the same calliper. What about Coopercraft?
http://www.coopercraft.co.uk/
Adam do you still have the old pistons?
I need little and large to see what they say at work
Russ

[LMJ]

Maybe Brookhouse has them for Twin Circuit. If you google: Volvo p1800 stainless brake piston, you get this:

B) Front Brakes P1800 with Twin Circuit - Brookhouse Volvo ...
http://www.classicvolvoparts.co.uk/p...ID=32&scID=174
Volvo 1800 1800S 1800E 1800ES - G) Brakes - B) Front Brakes P1800 with Twin Circuit ... FRONT GIRLING BRAKE CALIPER PISTON. FITS ALL AMAZON & P1800 TWIN CIRCUIT ... REPRODUCDED IN STAINLESS STEEL. PLEASE NOTE ...

But if you go to the link, there is nothing mentioned on Brookhouse site that the brake pistons are stainless. Better ask Simon at Brookhouse.

[swedishandgerman]

Originally Posted by tdz840

Of course Jag e types use the same calliper. What about Coopercraft?
http://www.coopercraft.co.uk/
Adam do you still have the old pistons?
I need little and large to see what they say at work
Russ

Funny that! A friend's dad set up Coopercraft. He told me that they used to upgrade e-type callipers with Amazon ones!

Apparently - don't laugh - a Sherpa calliper with 4 pistons bolts straight on and is a very, very good upgrade!

Are you saying you want my old set of pistons? If you're getting a set made, I'll have another set to do my Amazon saloon

[tdz840]

Originally Posted by swedishandgerman

Funny that! A friend's dad set up Coopercraft. He told me that they used to upgrade e-type callipers with Amazon ones!

Apparently - don't laugh - a Sherpa calliper with 4 pistons bolts straight on and is a very, very good upgrade!

Are you saying you want my old set of pistons? If you're getting a set made, I'll have another set to do my Amazon saloon

Adam
Will See what I can do!
Thing is loads of work going thru the company at the moment and 'rabbits' getting harder and harder to sneak in.
Perhaps if we can show there is a market it may be easier. Perhaps we can supply Simon??!
The dual CCT calipers are 4 pot I believe so therefore not suitable for the earlier cars
You going to the Southern BKV tomorrow?
Russ