My car is leaking brake fluid. I've been opening up the master cylinder, and pumping the brakes, then filling it up with brake fluid. Then I close the master cylinder and drive it. At first I've got some brakes, then it gets softer and softer and I have to pump the brakes more and more to get it to work. Then it gets to the point where even if I pump the brakes the pedal goes all the way to the floor and it doesn't really do much to help stop the car. Then whenever I go driving I have to do this all over again.

I know it's leaking fluid, but still don't know where. When we take off the master cylinder cap and pump the brakes, fluid squirts out of the front part of the reservoir but not the rear. Is this a hint? I unbolted the master cylinder and found no fluid behind it. What's the next step in locating the leak?

I assume you're not finding a puddle on the ground anywhere under the car. You might want to take a look at the inside sidewalls of your rear tires........look for evidence of some fluid being "spun" from the drake drum toward the tread. You could have a wheel cylinder leaking that doesn't happen to drop anything on your driveway.

Roger

If there is no fluid squirting up in one chamber of the MC, then it is likely bad, and that's the cause of your poor pedal/disappearing brakes. Is there any fluid leaking out around the MC gasket? You can pull the wheels/drums off too to see if there is fluid leaking too. Follow Roger's advice first.

Lou

_________________
Home of Slant6-powered fun machines since 1988