After replacing a brake cylinder, we started hearing a "drum" sound when applying the brakes. The "beat" slowed down as the vehicle slowed down. We replaced all pads/rotors and shoes/drums, and the problem quieted down for a few days, but is now getting worse and worse. It sounds kinda like a drum beat as the vehicle is coming to a stop. My husband the mechanic is stumped. There is no vibration and there is plenty of "brake pedal"
Brake problems on 1995 Pontiac Trans Sport
by tigermnm3132 in Ravenna, MI on September 15, 2009
1 answer 2 comments
ANSWER by patrick mannion , September 15, 2009
Can you pin point the sound to one side or the other. Could the brake drum be out of round. If you can say for sure it is from one side or the other take off the drum on the side the noise is coming from and mark the orientation of the drum to wheel hub, mark the wheel stud to drum and rotate the drum to the next wheel stud until the noise may go away if it does you may have found the proper index hub to drum. I had a similar problem with an old drum brake car. Other things that could cause this would be brake lining contamination due to a grease seal or brake fluid. Would love to hear what you find.
COMMENT by tigermnm3132 , September 16, 2009
Like I stated, we replaced both drums and shoes. We thought the same thing, maybe a bad drum, but we switched them around, and didn't make a difference. seems to be coming from the side we changed the brake cylinder, but not for sure. Everything is dry, no leaks or contamination. My husband is a mechanic, he has no clue what could be causing it.
COMMENT by patrick mannion , September 16, 2009
I would try pinching off the brake flex line to the rear brakes (at rear flex hose) and be careful drive the Chevy on a quite street and apply the brakes. See if for some reason it has nothing to do with physically applying the brakes at the rear wheels. Is the play in ward and outward at the rear drums? I had "new" drums before that were touching the backing plates. Love to hear what you find.