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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - Master Cylinder Source?

My car came without a master cylinder, so now that it's time to get that part of the car sorted I'm left with the problem of where to get one. I'd like to have one of the resleved units, but don't have a core to start with. Does anyone sell them outright, or do I have to buy a core and then get it done? Of course I could always spend the big bucks and get a new one from Moss or VB, but then they aren't sleeved and I would expect to have problems in the future. What's the board think?
Bill Young

New, from the factory, they weren't sleeved. They've lasted, in many cases, 40+ years without a sleeve. And sleeving doesn't eliminated problems. Sometimes they create them. Ask Gord Harrison!

TTFN

Derek Nicholson

Buy a new one. The seal kits on the market at the moment are CR*P, and the extra money involved is surely less than your life is worth.

I was going to put new seals into my rear cylinders when I R&R my rear axle completely this winter, but Bob West said not to bother as even the rear seal kits are junk and cause nothing but problems (he sent me a set of rear cylinders which I have returned because there is nothing wrong with the ones I have - I figured if I am doing a complete axle job, the brakes are going to need bleeding anyway, so a kit is just preventive maintenance).

Make sure that you get an MGA MC, not a Sprite / midget one. Although they LOOK the same, they have different bore diameters.

For the reservoir cover (not always included in the new ones), the high domed 1600 is not necessary even if you do have 1600 brakes, you just get a larger reservoir with the high cover. The cap is a standard Lockheed cap.
dominic clancy

Why is it that the small, simple parts are the ones that seem so difficult to reproduce?

I would rather have good seal kits, carb parts and screws than superchargers and such items.

Jeff
J Delk

Bill,
As stated, sleeves are not necessary and, in fact, sometimes are a problem. Two years ago I rebuilt my original 58 MC (honed, new seals and springs, original pistons)that had been sitting since 1981 when I took the car off the road. Works perfectly. Took the car to Watkins Glen in September and ran the old course and the new course, at speed, in traffic. As long as the bores clean up there is not much that can go wrong. Yes, there has been some trouble with seals, but most of the problems come from faulty installation. If you need a core, or parts, or a rebuilt unit try calling Cecilia at SF.

Cheers,
GTF
G T Foster

If you use an origional MC and hone it every time you clean up your brake system, over the many years will it not increase the diameter of the bore slightly? Is it not likely that this honing (increase sizing )is the difficulty and not the seals? I agree the quality of the seals used today is not the same as was used in the past but perhaps the extra diameter is not helping. Also does not sleeving offer the opportunity to return the bores back to their origional diameter (or if you wish a little tighter) therefore a better seal?

And finally, if you sleeve your MC should you lightly hone the bore BEFORE installing and using new seals?

Gordon
Gordon Harrison

I have never honed any brake cylinder - I never needed to with using Si fluid. Seals do deteriorate over the years (and are a wearing part anyway). The new seal kits do not fit my MC, which was new, and did not leak externally (just internally, the clutch side would not hold pressure). The Lockheed branded kits from three sources all caused pistons to bind in the bore. In the end I had to reuse one of the original seals (which looked fine and works fine too - the pedal is rock hard).

If Bob West says seals are substandard these days, I believe him (he probably sees more cars than anyone on this board). In the case of rear brakes, a new cylinder is about $55, a set of seals is $7, so if the cylinders are below par, it's not a big hit to change them.

If the MC is toast, I know it's a much bigger hit to replace, but then it is the key component, and I would still say that every penny is well invested. If a new one costs more than a recon unit, then I'd also say that it is money well spent - particularly if you use standard brake fluid as the leaks spiol your paintwork too!
dominic clancy

Thanks guys for the input. One of our board readers has offered to sell me a spare unit he has which may only need a seal kit, and if that doesn't work out I'll certainly try SF. It seems like the A will have a present under the tree this year after all.
Bill Young

This thread was discussed between 29/11/2006 and 01/12/2006

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This thread is from the archive. The Live MG MGA BBS is active now.