Caliper Rebuild / Refurb

[MattMe]

Hi.

I plan to rebuild my standard M16 front callipers (vented disc) whilst they're off the car. The nearside is definitely sticking so I'm going to buy seals and new pistons. I found a kit on eBay for £50 that includes 4 pistons and all the seals required.

It looks fairly straight forward, probably a job I can do in the 'workshop' (AKA utility room).
I don't have a vice or an air compressor, which I see a lot of people have used when undertaking their calliper rebuilds, but I'm sure I'll manage... I hope.

Just a couple questions as I know there are a couple thread on it already:

Will the callipers require splitting to change the pistons, and if so will I need to replace any more parts at the same time?

I thought I might paint them whilst they're apart, just boring silver. Anyone have any preferred VHT paints I should look at? Other than degreasing and removing surface rust with a wire brush is any more prep required?

Cheers,
Matt

[340truck]

The calipers will not need splitting to change the pistons, however if they are sticking they could be trick to remove. As you are replacing them, you may be able to lever them out but you are likely to break the lip for the dust boot. If only one piston in the caliper is stuck, I would keep the caliper on the car and connected, clamp the "unstuck" piston and use the brake pedal to force the other out, have the engine running for servo assistance.

[Stewb28i]

As 340 said getting the pistons out without compressed air is tough although not technically impossible. If you have a properly seized piston sometimes only hydraulic pressure will do. You can make sure all of the pistons have moved prior to removing from the car.

As an aside I had the calipers on my 2.8i refurbished professionally through a local motor factor. They charged me £45 inc vat per caliper & the turnaround was 2 days. They came back as new. They'd been fully cleaned, re zinc plated, 3 new pistons, new seals (obviously), new bleed nipples, they'd been split with new bolts fitted & even came with new pins, R clips & pad shims! I was mightily impressed, seems like good value if the kit is £50 for the non vented type calipers.


Stew.

[pbar]

You can use a footpump to bring the piston out, it worked for me when I had a siezed one. (Thanks for the tips Steve). Use one of those tapered football/airbed adaptors on it, fits just right into the caliper. It can come out with some force, so plenty of rags in there.

[Stewb28i]

I've had pistons (in bike calipers) with more than 150 psi & no shifting! To be fair they were ally calipers which were very furry! I ended up having to use the master to push them out (with some heat).

Cast iron isn't quite so bad from a corrosion perspective.

Stew.

[rshyndy]

A grease gun also works providing you get the right thread adaptor to screw into where the flexi hose goes.iv used this method several times and Its never failed me yet. Makes a mess but does the job

[pbar]

I found a kit on eBay for £50 that includes 4 pistons and all the seals required.

You can get an M16 caliper for £39.50 (ex. VAT). Although granted, you may need the spacer kit also.

http://www.rallydesign.co.uk/product_in ... s_id=10537

[MattMe]

I believe Rally Design sell a vented disc pair for ~£110 plus shipping, but they're cheap copies that "sometimes require modification to fit correctly".
That put me off a little if I'm honest.

I've spent £50 on the rebuild kit, £2.50 on 2 new bleed nipples and £10 on paint. They'll be as good as new after that, although it probably will also include bloody knuckles and plenty of swearing to get them done

[pbar]

Fair enough Matt, that would put me off as well to be honest. Sounds like you have it covered. Good luck!

[MattMe]

Fair enough Matt, that would put me off as well to be honest. Sounds like you have it covered. Good luck!

Well, we'll see, won't we? No doubt it a couple weeks there'll be a new thread by me titled 'M16 Caliper Advice Needed'!

[Andrew 2.8i]

Hi All,
The Capri Club sell reconditioned calipers for £100.50 including a £35 surcharge. Therefore, £131 a pair for members, once you've returned your old items.

The Rally Design calipers with spacer kit work out at £120.60 a pair. If they're as poor quality as suggested, perhaps the CCI items would work out as better value for money.

All the best,
Andrew.

[nigecapri]

Euro Carparts for a tub of RED GREASE Suitable For Rubber.
Use this in the seal grooves & everywhere outside the seals. Wipe a smear inside the dust boots too.
As 340truck said - whip the pads out, get an idea of where the pads are then press the pedal a bit, check again to see what's moving or better still get an assistant to check. If on pad is sticking then lock the other side with a hammer shaft etc so the stuck piston moves. Nudge them out as far as you dare then callipers off. They should then pull out easy.
If you pedal-press them all the way out you risk spraying brake fluid everywhere.

[Stewb28i]

Never thought of the grease gun - good call!