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 - Breaks


Right, heres the problem: no brakes, nearly no fluid left in the master cylinder, and lots of white smoke when running. Also, brake fluid in the pipe that leada from the engine to the brake servo. Went to the garage to get advice and parts and was told this is a common problem- the rubber seals in the master cylinder go alowing fluid to escape into the servo and then on into the engine. Thus, fix the master cylinder and all will be ok. I was totally pleased as I was half expecting a new servo and engine!! Now I have actually begun to do the work I can't see how this could be the problem at all. Anyone shed any light on this? Also I would be interested in knowing how the brake system works and where all the brake pipes lead. Thanks for all of your help!!
Ed

By the way the car is an original 1974 B roadster... ...ooops!
Ed

Ed

Do yourself a favor and buy a maintenance book for the car. The pictures in the books answer 1000 questions.

There's a check valve on the servo end of the hose that goes from the engine to the master cyl. Make sure it only allows you to apply a vacuum to the servo. Also make sure the servo doesn't leak: suck on the hose if you don't have a vacuum pump and gauges.
The pipes on the master cylinder go 1 each to the front disc calipers via rubber hoses. Get under the car and eye-ball these. If they're rotted, get new ones, they're cheap. I think there's only one pipe going to the rear wheel cylinders, it gets split at the union at the back axle. Check the rubber there as well. I've rebuilt rear wheel cylinders before but its probably easier to just replace them. They're not too expensive either.

I don't remember how the servo goes together with the MC exactly so I don't know if the MC needs rebuilt or the servo itself but if it is only the MC that needs rebuilt, at least disassemble and clean the servo to get all the brake fluid out.

Mike
Mike Phillips

Ed,

The servo is operated using the vacuum created by the inlet manifold. This will be via a hose approx 3/4" dia. between the two units. The vacuum operates a diaphram inside the servo which sometimes splits allowing brake fluid to be sucked through the vacuum into the inlet manifold and finally burning to produce exhaust smoke.
It is worth checking the servo as the master cylinder may be fine.

Dave
dave

This thread was discussed between 06/04/2003 and 08/04/2003

MG MGB Technical index

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