Brake have been sitting since 1990 - replace or rebuild?

[tdskip]

A good weekend and a good holiday season so far.

My S4 Elan Has been sitting since 1990, so obviously all of the brake hydraulics need to be redone or replaced. My question, if I may, is what would you suggest doing here. I?m in the United States and a, wondering if there?s a service that rebuilds our brake calipers that I should send these off to, or if it will be a better choice to source replacement ones?

I?m going to try to rebuild the brake master cylinder because the bore looks OK.

Thanks!

[SENC]

You won't find replacement rear calipers, they are no longer made. Several of the usual vendors, though, will sell rebuilt calipers on an exchange basis. If yours look ok and can be operated, then replacing the pistons (with ss pistons) and seals should be simple enough.

Here is one of the better threads on caliper rebuilding:
viewtopic.php?f=42&t=22999&start=

[tdskip]

Thanks

[benymazz]

There are (in my non-expert mind) four areas to consider

1) Master cylinder. This will need to be rebuilt and after it's rebuilt you'll probably either find that it works great as it should or that it leaks. Obviously if it leaks you'll need a new one. Not too hard to find, easily sourced from the usual suspects.

2) Caliper pistons. My information here is shoddy but the general principles will apply. I believe that the Girling calipers used in the Elan originally had chromed steel pistons which are obviously vulnerable to rusting once the chrome is goes away. If this is the case (or even if it isn't - stainless pistons are relatively inexpensive and I believe have a lower thermal conductivity than carbon steel which is better for a brake system) then the pistons will need to be thrown out and replaced.

3) Caliper castings. Despite what the Lotus manual says you can and should split them in half (buy new crossover seals) and make sure that all fluid passages are clean and free of rust. A sandblasting and a new coat of paint or zinc plating is a good choice at this time. Obviously the pistons bores should be cleaned (steel wool or light grit sandpaper to remove rust) and the piston seals replaced too.

4) Brake lines. I do not know what kind of hard lines were originally used on the Elan but I assume that they were steel which is obviously vulnerable to rust. Usually this happens from the outside in and not vice versa but I know you can buy a full set of replacement copper lines cut to length with flares already added from Kelsport in the UK so you do have options here. You will also need to consider if the rubber/braided lines that run from the hard lines to the caliper are in good condition or not. Regardless of what if any lines are replaced they should be flushed thoroughly with brake fluid until it runs clear and not compressed air. Compressed air can contain oil or moisture from the compressor which will contaminate and (in the case of oil) mix with brake fluid and form a mixture that will eat rubber seals.

This is just my understanding based on what I've read and if I have said anything wrong here or given bad advice please correct me and I will edit this reply. Obviously braking is an area where giving correct advice is of critical importance.

-Ben

[tdskip]

Excellent post Ben, thank you.

[patrics]

Hi
Assuming all was good before storing then the minimum you could get away with is to replace the caliper seals as these will have taken a set. Also if available then replace master cylinder seals.
Also don?t forget the clutch.

Regards
Steve

[alan.barker]

You can get Stainless Caliper Pistons in the US for a very good price. I think i was supplied by "Farrel" or something like that. It was cheaper for me to buy in US including postage than from in UK and sent to me in France.
Alan

[69S4]

I don?t remember the stainless pistons I bought in the U.K. from P. M. being all that expensive? I even bought an extra pair for the rears a couple of years back by mistake and didn?t curse myself for the waste of money.

[pharriso]

RDent's SS Pistons are $40/35 front / rear

Matty's are ?18.50 front & rear

[tdskip]

Are the caliper seals quality and easy to source as well?

I?ve never split a brake caliper before....

[pharriso]

Are the caliper seals quality and easy to source as well?

I?ve never split a brake caliper before....

Rdent has them:

Ref. 26J4908 Caliper Cross-Over Seal $2.50 each
The small square-section ring seal fitted between the two caliper halves. If you split the caliper you should replace this seal. One seal required per caliper.

[tdskip]

Yes but we?re shipping that would be like 12 bucks total, kind of pricey.




So if it?s that straightforward is there any reason not to rebuild these things myself?

[pharriso]

No, just take your time & clean everything meticulously as you go. Wet new seals with brake fluid (dot 3 or 4 not 5) & use red rubber grease on the caliper dust boots.

[tdskip]

Thanks Phil, think I will give this a go.

[gjz30075]

I split the halves on my calipers and if they were nasty inside, I let them soak in a pail of Evaporust
overnight and that has always cleaned them up.