MGB: Brakes go to the floor

Hello all,
Had a scary moment today on the highway...a car cut me off and when I hit the brakes they went down to the floor. I had to pump them. By the second pump I was able to stop the car. When i got off the highway and drove on the local streets,,same problem. The brake pedal will go to the floor and then I have to pump the brakes two or three times to stop the car. I checked under the hood and I see two screw on tops near the master cylinder. They are both filled with clear fluid. I am thinking its the master cylinder at this point. Your suggestions are most appreciated.

Do NOT drive the car again until you get this fixed!

Anything dripping down on your pants leg on the driver side?

Check your wheel cylinders as well.

Your not using silicon are you? Silicon was originally designed for hill climbers due to it's high boiling point but they soon found it's problems. Water is not absorbed, collects in the lowest spot (calipars) and boiled when it got warm. Racers who use silicoln change their brake fluid before every race.

I bought the car a few weeks ago...I dont know what brake fluid is in there. How should I proceed? I also don't have any brake lights all of a sudden!! Double whammy for me.

If you don't know how long the fluid has been in there I think I would deffinantly flush the system and put new fluid in. You will need to know what kind of fluid was in there though.

Brake lights are usually just a bad switch which is right on the cover of non-boosted early cars or on the backside of boosted late cars.

Yes, probably the master but could also just be air in the system from any number of failures including the last person to bleed- but any decent MG owner should be able to tell this problem within 1 mile of driving if they have owned a car for any length of time.

Is this a converted car or a standard car?

-BMC.