Hi All,


Got a question with my brakes. I have a 73 F-250 with drum brakes and power booster. About a week ago my brakes started acting funny. Sometimes they work normal, sometimes a little soft and other times nothing unless I pump them once. Now I'm not sure but messing with it this weekend, I noticed that when in park and at a idle. That when I press on my brake pedal the idle would change. I never paid attention to that before, could my power booster be going bad? Is there a way to test it? I thought of running it for a day with the vacuum line feeding that removed and plugged. Fluid level was fine but the master cylinder cap gasket could be changed its not very soft anymore. However no parts stores seem to carry that Thanks Mike

 

Sounds like it could be a booster. With the engine off, pump the break pedal untill it is hard (all vacume is out). Hold the break pedal down, not letting up, start the engine. If the booster is working, the break pedal should fall some after the engine starts.

If the pedal dosen't fall some, it would sound like you have a booster problem.
Bob

 

If you have to pump the brakes up, it's not the booster. It could be a master cylinder that is on its way out. If the seals are starting to fail, it could work fine sometimes, and others require pumping it up to regain a proper seal.
Another reason to change your brake fluid just like any other fluid.