I can hear what sounds like an air leak when I initially press the brake pedal. The pedal holds pressure fine when the car is off, one pump brings the system to pressure. When I start the car, the pedal can go lower than I think its supposed to, and remember it. I've got no problem with braking power. Is this a symptom of a Booster leaking? I first noticed it when I changed the front pads recently. I used channel locks to spread the pistons to fit the new pads, like I've done for years. When I reassembled, I noticed the air venting sound inside the car.

The check valve fitting visually looks ok. But I'm thinking the sound I hear inside probably means a diaphragm leak? After 19 years not bad I guess.

I looked on FCP and there boosters are 295, and NAPA has an OE Bendix for $129. Anyone ever buy one from NAPA??

Replacement looks very straight forward. A mornings job for a first attempt. Does the master have enough play once its unbolted from the booster to move it enough to clear for the booster removal?