93 towncar brake pedal goes to floor--sometimes

[1977 Greyghost]

Greetings to all. I have a 93 Towncar and recently the brake pedal has
strted to go to the floor, sometimes. My wife first clued me into the problem about a week ago, she said it happened to her aboiut 3 times when she was out in the car. I checked and added a small amount of brake fluid, have driven the car about 100 miles since then with no problems. Then while in a parking garage I went to stop and it went to the floor! This happened one more time to me while I was driving that day. It only seems to happen at low to idle speed...thank goodness.
It does have the anti-lock system which has been inoperative for about a year with no problem other than no anti-lock. I suspect that the master cylinder is by-passing but would appreciate any imput and advice.
Thanks for your help. 1977 Greyghost

[junk yard doggie]

Hello

Yep, that definately sounds like the master cylinder to me. You probally will want to get that replaced right away before it goes out completely.

Mike

[SUERED]

Check the vacuum line to the power brake booster. I have been told by a mechanic that if you panic hit the brakes and have a weakened vacuum hose, it will collapse and cut off engine vacuum to the booster--result: loss of braking (takes lots of effort). Check those lines for oil contamination and weakness--as one possibility.

[sreilly77]

Originally Posted by 1977 Greyghost

Greetings to all. I have a 93 Towncar and recently the brake pedal has
strted to go to the floor, sometimes. My wife first clued me into the problem about a week ago, she said it happened to her aboiut 3 times when she was out in the car. I checked and added a small amount of brake fluid, have driven the car about 100 miles since then with no problems. Then while in a parking garage I went to stop and it went to the floor! This happened one more time to me while I was driving that day. It only seems to happen at low to idle speed...thank goodness.
It does have the anti-lock system which has been inoperative for about a year with no problem other than no anti-lock. I suspect that the master cylinder is by-passing but would appreciate any imput and advice.
Thanks for your help. 1977 Greyghost

you can also try to bleed the brakes to see if you might have air in the brake line. but i also think that your brake master cylinder is bad. but you never know you might get off lucky