MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

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 MGB Technical - Failed master cylinder

I bought a brand new master cylinder two years ago from Brit-Tek (73 B). It worked fine for about a year, but it began to leak last summer. I pulled it out and opened it up far enough to find the final seal installed backwards. I turned the seal around the correct way and all was well...until recently. It's started to leak again. I don't drive the car very often (it's a fair weather cruiser)so I haven't abused it. Any ideas what to do now? It's well out of any warranty, though I should have called Brit-Tek and told them about the seal orientation. Another new one is gonna cost what I consider a fortune, and who's to say it won't do the same thing. I would rebuild this one but I have heard that rebuilding one all the way is very tough to do without special tools.

I just hate to keep taking the MC in and out, as that little excercise is not a real joy to do over and over. I'd like to do this just one more time and have it last for at least more than a year or two. Suggestions?
Mark T

Mark - Have you considered getting a repair kit for the M/C and rebuilding it yourself? It is not a difficult job and the only thing besides the kit that you will need is a cylinder hone. The next time you have reason to remove them, install helicoils in the holes in the mounting flanges. You will use a kit to install 5/16 - 24 helicoils. The holes in the mounting flanges are close enough to the proper size that they don't need to be drilled, just tapped for the helicoil. After installation of the helicoils, the mounting bolts are just screwed in from the front of the pedal box and tightened with a 1/2" 1/4 drive socket. I ground off the 1/2" socket I use to make it shorter and getting it onto the lower bolt somewhat easier. From there on all the bolt turning can be done from under the hood, without having to reach in from inside the passenger compartment (except for the brake and clutch line connections). Good luck - Dave
David DuBois

Mark, I own a 1974 MGB. In the last 4 years I have put 4 new Lockheed brake master cylinders, 1 rebuilt that lasted 1 year and 1 that was brass sleeved I sent back 4 times. They all leak out the front seal. The new master cylinders lasted from 2-6 months. I've used Castrol LMA for the last 28 years. Never had a problem until 4 years ago. It sure is a pain to clean the mess up and repaint. Good luck, Jerry
Jerry Patterson

Hence the reason for using Silicon fluid. Is this yet another case of the rubbers swelling ?
Iain MacKintosh

This thread was discussed between 03/02/2005 and 04/02/2005

MG MGB Technical index

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