Practically Classics Forum

My Wife's Mx5 (Eunos) is losing brake fluid but pedal pressure is very good and it's stopping straight and true. It's 1991 manual with no modifications. I think it might be losing it through the servo but I'm not seeing any under the servo. It is a bit pinky after braking but I'm also not seeing any obvious white smoke. The vacuum pipe from the intake Manifold is a bit hard and brittle but no leaks or holes.
Any ideas? I haven't had a chance to check the pipes or cylinders.

I reckon you're thinking in the right direction - have a good look around the cylinders, calipers and master cylinder and if they're all bone dry it's probably the servo - have a look in the servo vacuum pipe and see if there's any dampness in it, should be a good clue.

Also worth checking the flexi hoses for dampness, especially if there's a hidden one or two going to the rear brakes, which might not be so obvious.

All the best with it!

Thanks for that, I'll do a full run through and check the vacuum pipe from the manifold.

On most servo's it's possible to pull the vacuum pipe out of the servo and 'dip' something into the unit (I use a cable tie) to see if there is fluid in the bottom of it.

Thats a good idea to "dip" the servo. Didn't get a chance to look at it today as she was working.
Can you recondition the master cylinder and servo or are they disposable items only?

Diesel Fionn wrote: Can you recondition the master cylinder and servo?

Yes, though depending upon how much - if any - bore wear you find when you disassemble the master cylinder, you may want to have the cylinder sleeved or fit a new one.

Diesel Fionn wrote:or are they disposable items only?

Absolutely not in the case of the cylinder, though very few servos are well suited to DIY dismantling and reassembly because their seam tends to be folded and crimped together and that's before it's filled with solder to seal it.
BUT.. If the servo is found to have fluid inside as a result of a leaking cylinder, there's no reason not to reuse it once the cylinder has been repaired or replaced, subject to the servo being removed, drained and flushed out with hot water followed by a scoosh of something harmless such as WD40, which will prevent it from rusting away as soon.

Well the vacuum pipe was bone dry as was the servo. The fluid is coming from the handbrake assembly on the rear nearside brake caliper.
So now I'm wondering is the caliper toast or can I rebuild it. Has anyone seen this before???

Ive rebuilt them before now. Rebuild kits are available but the best solution for a car that is used daily is fit 2 refurbed units to the rear.
The handbrake mech is tricky to strip and rebuild succesfully imo.
When i refurbed my mx i made sure to use copious amounts of the correct lube/anti-seize in the relevant areas.

Kev

Seconded - a pair (or just the one if you're feeling tight) recon exchange calipers and you'll be sorted.

Cheers

http://www.mx5parts.co.uk/rear-caliper- ... p-380.html

Worth considering.

Kev