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MG Midget and Sprite Technical - Brake Master Cylinder Leak

I have a leak which I assume is from the Brake master cylinder. I have a tell tale drip from the brake pedal onto the footmat beneath which I believe is typical.

Never repaired anything like this before and I see in the Moss catalogue that there is a repair kit at £7.45. My question is how easy is this to do and how is it done and whether I should replace the master cylinder itself as a matter of course, given we are dealing with the brakes.

Car is a 1974 Mk3 RWA midget GAN5.

Any help very much appreciated.
Andy Davies

Andy:

If you have not wrestled with other Midget mechanical issues lately - I would suggest that your leaking Brake Master Cylinder would NOT make a good first repair project. The low cost of the rebuild kit can be very attractive - but once you try and take it apart, you will quickly get an appreciation for how difficult it is to "get it right"...

It's fun to go fast...but it's even more important to stop faster!

This is one of those little projects that I would describe as a "velvet lined mouse trap"...

Mike P.
Mike Pelone

I was told changing seals is not favoured, i.e. buy and install a new M/C
Nigel Atkins

New master cylinder is the best way.
pd cumbers

The original maintenance schedule calls for the brake seals to be replaced every 30.000 miles, or Three years. So are we saying that the master cylinder has to be replaced every Three years. That seems a bit over the top.

Dave
Dave Barrow

there's absolutely no reason why you should not fit new seals in the existing master cyl. It's not rocket science and as long as you are logical, not too ham-fisted, and able to interpret and understand manuals then go ahead. The rebuilt m/cyl will either work or not and this is tested at 1 mph in your drive not at 40mph on the main road!
David Smith

Andy. as David says, be logical, take your time and it should be OK. Once you've got it on the bench and are taking it apart, as stuff comes away, put it on the bench left to right as it comes out of the cylinder, then hopefully you won't get mixed up once you've fitted the new seals. Re-assembly is the reverse of dismantling, as they say in the manuals. most manuals have exploded drawings to refer to if you do get it wrong.

Bernie.
b higginson

And use plenty of Brake fluid on the new seals as you fit them.
Dave Barrow

This thread was discussed between 10/08/2010 and 11/08/2010

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