Brake pedal problems

[kmsnsx]

My brakes seem to work fine, but once I come to a stop and am holding the brake pedal it slowly keeps going down. I can pump it once to regain a solid pedal. Brakes have been bled twice with seemingly no air in the system. No apparent leaks to the system and fluid level stays constant. Any thoughts on what would cause this?

[jlevie]

No apparent leaks and a sinking pedal says that the master cylinder is bad. If it leaks the fluid goes into the brake booster and thus isn't visible. The downside to that brake fluid will destroy the brake booster diaphragm in short order. Remove the master cylinder and booster and see if there is brake fluid in the booster. If so replace the booster and master cylinder. If the booster has been exposed to brake fluid and you only replace the master cylinder, you'll soon be removing it to replace the booster. If there's no brake fluid in the booster, just replace the master cylinder.

[kmsnsx]

Thanks Jim, that is what I suspected. Hope to see you at the track this year!