MG Car Repair: 1977 MG Midget, brake master cylinder, piston seal


Question
Ok, first things first, we are not fix it people. We are very, elementary soooo, we
started our midget after about 7 months and the brakes don't work. Do you
think it is the fluid? And we don't even know where the brake fluid container is.
Please advise and thanks.

Answer
Hi Janet
Nice to see an owner take an interest in their car.

When you say the brakes don't work, do you mean the pedal drops to the floor, or does the pedal feel normal but the car doesn't stop?

If the pedal drops to the floor, then it could be a lack of fluid.  However,if you leave a car for 7 months it shouldn't lose any fluid.  Loss of fluid usually means you have a faulty rubber seal, probably in the master cylinder, but possibly a rear brake piston seal or a brake hose with a hole in it or a rusted brake line.  If you look around for a puddle of brake fluid, that should give you a clue. I don't think you have enough knowledge to repair this fault yourself.  After all, brakes are a safety-critical component, and if you make a mistake it could be fatal.

If the pedal feels normal (or stiffer than normal) then you have not lost any fluid, so you don't need to top it up.  This usually means the pistons in the front callipers have seized with rust.  Usually it only happens on one side, and the car pulls to the other side when you apply the brakes.  If the car is parked outdoors then that will make things worse.

To answer your question, the brake master cylinder is located immediately above the brake pedal.  The fluid container is mounted on the top of the master cylinder.  It is accessed by raising the bonnet (hood).  You can use any make of brake fluid so long as it is rated as DOT4.     

I suggest that you obtain an owner's handbook for the MG Midget.  This will tell you all about routine servicing.