Before I split these callipers...

[JonB]

Hi

I'm restoring a set of callipers on my S4. I found this useful post from ceejay that talks about the rears: https://lotuselan.net/forums/viewtopic.php?f=42&t=22999. Also, another thread discussing fronts (which I can't find now, sorry). In both instances, mention is made of splitting the callipers; this in turn means the inter-gallery seal must be replaced. I found reference to a seal for the front callipers - sold by Moss under part number 583-820 (https://www.moss-europe.co.uk/seal-between-caliper-halves-583-820.html) but what seal would I need for the rear callipers, and what torque specs are required for the bolts, front and rear, when reassembling?

I might attempt restoration without splitting but I can see getting into the bores to clean out and replace the seals, especially on the rears, is going to be a bit of a pig.

Cheers
JonB

[2cams70]

Personally I don’t split calipers. There’s no need to unless you want a concourse looking restoration. You only need to split the caliper if the seal between halves is leaking. I’ve never come across one that does. The seal should be a non wearing item. It only fails if it’s been in contact with mineral based oils (eg. someone has used kerosene for cleaning or pumped grease in to extract the pistons). It’s possible to flush the fluid gallery between the two halves with methylated spirits pumped through a trigger spray. There was never any torque specification given for the bolts because the caliper manufacturer recommendation was always to not split the halves. If you remove or replace the bolts what you are dealing with then becomes an unknown. Granted many people do split calipers and replace bolts seemingly without issue. I’ve never had an issue cleaning the bores with steel wool and emery with the two halves together. If you want them pretty they can be painted rather than plated.

[JonB]

I know that the makers say you shouldn't, but there seems no reason not to - as long as you can get the parts. I'd rather not myself, but as I say it looks a difficult job to clean the inners with them together. Not planning to get them plated, I'll happily spray with caliper paint.

[Andy8421]

I rebuilt my rear calipers a couple of years ago. If I recall correctly, the caliper half seal was the same as the front calipers.

I found the whole process a complete pain. Given the costs of the repair kits, new pistons and spares to repair the worn out bits of the handbrake mechanism, it would have been about the same cost have had them rebuilt and plated professionally.

[JonB]

Thanks Andy. What are the wear points on the handbrake mechanism, and is it easy to detect wear? Main reason I’m asking is mine seem in very good nick, still have original silver paint and the handbrake mechanisms seem pretty tight.

[2cams70]

You don’t need to be too fussed about the area in the cylinder bore below the piston seal. It’s the area of the bore above the piston seal that causes most of the issues. Water creeps in here past the dust seat which corrodes the cylinder in this area and causes piston sticking. The area below the seal on the other hand is only exposed to brake fluid. You might get some minor pitting from brake fluid absorbed moisture here but it’s not critical and doesn’t cause issues because the cylinder wall in this area is not a sealing area

[jono]

Having just done this job, as others have said I would not do the rears again - send them off to Classicar Automotive who will do a superb job at probably a similar cost that you could do it yourself but without all the hassle.

The fronts are quite straight foward though and worth doing if you want a project.

I can't imagine what a PITA it would be to do them properly without splitting them though.

[ericbushby]

+ 1 for Classicar Automotive.
They seem to have changed every part except the castings, even the bleed nipple.
The callipers just looked new and at a reasonable price. Should be good for another fifty years.
I do a lot of work myself and I understand it is satisfying to do so, but this is one job that is better done by the experts and apparently does not cost much more.
Eric in Burnley
1967 S3SE DHC

[661]

Having just done this job, as others have said I would not do the rears again - send them off to Classicar Automotive who will do a superb job at probably a similar cost that you could do it yourself but without all the hassle.

.

^^^^^This

[2cams70]

I can't imagine what a PITA it would be to do them properly without splitting them though.

For the fronts at least it's dead easy. Even easier in fact if you don't split the calipers because it's one less operation. Plus if you DIY you have control over the parts that are fitted. For example for my calipers I was able to source new old stock original Girling pistons manufactured to correct tolerances and not made out of stainless steel.

[JonB]

Sorry, I have to ask as there is no info on their web site - how much does Classicar Automoitive charge to overhaul rear and front callipers?

I could call them but it's quarter past eight in the evening...

Thanks!
JonB

[ericbushby]

Hi Jon,
My front callipers were £60 each recently but may have cost more if I had not called in to collect them.
PM sent.
Eric in Burnley

[JonB]

Did they fit SS pistons or steel chromed?

[ericbushby]

Hi Jon,
I don`t know and didn`t ask. Is that a bit sad?. I suppose they know a lot more about it than I do and I have no preference.
As said before I was well pleased with the result and could not have done the job as good myself.
Cheers
Eric

[billwill]

Sorry, I have to ask as there is no info on their web site - how much does Classicar Automoitive charge to overhaul rear and front callipers?

I could call them but it's quarter past eight in the evening...

Thanks!
JonB

Odd! Their advert in Club Lotus magazine usually shows prices (I think).

The rear ones are more expensive as the parts are now rare, I think.


There used to be problems with their advert, because the email domain & website domain names had a typing error. I did tell them some time ago & they seem to have dropped the website from the advert. I've just tried various possible website addresses & cannot connect.

Check by emailing them on [email protected] or phone 01625 860910

The Jan 2023 Club Lotus magazines states re-manufactured front calipers at £57->£65 and Elan/Plus2 rears including handbrake at £185.

Be wary of using google search for [classic brakes] as it seems to throw up websites which are not the firm we are talking about here. Classicar Automotive at postcode SK11 9AP is the one we mean here.