Rear brake caliper dismantling ? any advice?

[PhilBell]

I'm thinking of splitting the calipers on my 1962 fhc to make seal replacement and cleaning/painting (or plating) easier.

Is it as straightforward as it appears?

[JagWaugh]

It is indeed. Get them plated, paint, even the special 2k brake paint hasn't worked for me.

For the front calipers you will want to replace the square section o-rings. Pegasus racing has the correct ones.

Andrew

[richard btype]

I'm thinking of splitting the calipers on my 1962 fhc to make seal replacement and cleaning/painting (or plating) easier.

Is it as straightforward as it appears?

Phil - Straightforward but definitely plating? If you don't know them, you have a good company down the road in Arlesey SG15 6SG all the finishes except Cadmium!

[ralphr1780]

Phil, it is straightforward if the IRS is on the floor, just been there last week.
You need to get the front shocks out of the way, then you can remove the 4 bolts holding each caliper. The right inboard one will have a bolt difficult to get to unless you reach it from underneath with a long spanner.
If you intend to keep the same hydraulic pipes, you will have to take every side pair together out.
I decided to put new calipers instead of reconditioning, given the various experiences related by other fellows.
Good luck.

[PhilBell]

IRS is spread around my garage after the latest diff rebuild. Just tried to blow out the piston using my mountain bike track pump connected to the caliper via a short length of brake pipe fitted with a threaded union. 120psi made it groan slightly but I can only measure 1mm of movement. Off round to my friend's place tomorrow to try his compressor.

[vee12eman]

Hi,

Having had trouble removing pistons from an S-Type rear caliper recently, the simplest tool (after an air compressor failed), was a brake bleed nipple ( mine was brass and easy to work with), drilled and tapped to accept a grease nipple and then use a grease gun. No risk of pistons flying around, a bit dull but gentle and simple. I can post a picture of it later if desired. Took 10 minutes to make and 10 minutes more per caliper to use.

Regards,

Simon

[PhilBell]

Compressor-owning friend has just pointed out that his device tops out around 100psi, whereas track pumps max at 150psi ? if you've had three Shredded Wheats for breakfast ? so the compressor is unlikely to help.
I like the sound of the grease gun method.
And if I get the calipers apart in time (my Le Mans 24hrs trip isn't far off now) I'll investigate the local plater that Richard recommended.

[JagWaugh]

Hi,

Having had trouble removing pistons from an S-Type rear caliper recently, the simplest tool (after an air compressor failed), was a brake bleed nipple ( mine was brass and easy to work with), drilled and tapped to accept a grease nipple and then use a grease gun. No risk of pistons flying around, a bit dull but gentle and simple. I can post a picture of it later if desired. Took 10 minutes to make and 10 minutes more per caliper to use.

Regards,

Simon

If the calipers are empty from having sat and the brake fluid has leaked out, pre fill the calipers with water before you fit the grease fitting... Saves using a bit of grease, and makes cleanup easier.

[1954Etype]

Plus 1 for Vehicle and General platers. We use them all the time.

[PhilBell]

In the end I opted for plan C, which involved a 3-leg puller.

To give the puller's central threaded bolt something to push against I bridged the brake piston with a couple of UJ bearing races/end caps (sockets would do) and a steel bar (jemmy) across the top of them.

With this setup the piston moved quite easily and progressively, so i was in good mood on Saturday afternoon, even when I discovered that all four cylinder bores are rusty enough to warrant replacement. It seems the outer boot allows water to get in, corroding the piston and cylinder bore. In my experience cleaning off the rust isn't a good solution because any pitting left will compromise the sealing. And as much as I love removing rear axles (three times in six years), I'm looking for a fit and forget solution.

So I looked up the price of a new set of cylinders with pistons: ?367 in cast iron, ?908 in stainless steel.

Ouch.

[tinworm]

A grease gun can supply much more pressure than a workshop compressor and will shift any seized piston. Make sure no grease (if using ordinary general purpose grease) remains inside after the strip down as it will wreck your new seals. I wash everything in methelated spirit and dry out - but there are other cleaners available.

best of luck Barrie

[mgcjag]

Hi Phil...Glycol-ether (DOT 3, 4, and 5.1) brake fluids are hygroscopic (water absorbing), which means they absorb moisture from the atmosphere under normal humidity levels. ... one of the main reasons to change the fluid .....

[PeterCrespin]

Just fit cheap S2 or 3 or XJ6 refurbed rear calipers of the normal type with seals in the bore wipng the piston, instead of vice versa.

[PhilBell]

Other options for sorting the rusty cylinder bores are new stainless cylinder/piston kits from Zeus and cylinder relining by Ward Engineering.

Anyone got any experience of either?

[richard btype]

Phil

I have not as yet but do intend to have my original callipers re lined with the stainless sleeves when the car is restored, as like yours the rust/pitting etc was not acceptable and it will be nice to have the originals on the car - but not only for the sake of originality?.

To get me by as the car was needed back on the road at the time, I did opt to fit some stainless steel callipers which were sourced from I believe the USA via a well known UK parts company and they were expensive.

So it was very annoying to discover that one of the ss callipers (with less than 4k miles of use) failed in its second year, it was leaking through the casing as the construct was basically a two piece. It took ages to pin point the problem of weeping through what was a hairline crack and of course the items were now out of warranty!

You might get the impression that I'm not a great fan of newly manufactured items and the more I experience the poor quality of such items the more that statement would be correct!

[PhilBell]

Hi Richard

Just ordered a set of Zeus stainless rear cylinder/piston assemblies, which with a larger piston area will also help balance the Coopercrafts already on the front.

I liked the idea of having my originals relined but with the ratio of jobs to do and time left to Le Mans looking less appealing by the day, opted for a quick fix. I noticed elsewhere on these forums that David has Zeus on on his car, so took that as a good sign.

I'll keep my standard calipers on a shelf alongside the Girling dampers, original starter motor etc.

[Heuer]

Yes, I have Zeus all round on my OTS and they have done 50,000 miles over 15 years without problem.

[richard btype]

Phil

Are you still experiencing problems with the diff?

[PhilBell]

It's completely silent at the moment, mainly because it's still sat on my garage floor.

I had it rebuilt by Ken Jenkins. Turns out the pinion shaft was bent 0.003in, which is why it kept destroying crownwheels and pinion shaft bearings.

As soon as the caliper bodies and other brake bits come back form the platers I can throw it all back together, in between sessions helping my friend put his Alfa 2000GTV back together.

How's yours coming along?

[richard btype]

I find it not only sobering but also a right PIA fettling these classic cars! Is this the reason why the very high end restorations cost as they do? in that every single component is a potential let down or requires a higher level of awareness?

This could be the subject of some collective thought and experience! Currently have a problem with a leaking water pump on the Elan - yup its an engine out job and it was assembled with the utmost care and attention to detail.

The E is due a visit to Shropshire next year?

Good luck with the diff, sounds as though you may have a clear cause this time...