First off, I’ve never been inside a booster unit’s guts before so my knowledge of their inner workings is sparse.
I have a used booster I put on my 67 GTX years ago and it’s never seemed to do much as brake effort remains high. But since holding the brake pedal down while starting the engine causes it to drop a bit and then firm up, I figured it was working - at least somewhat. Finally I got around to pulling the hose on the check valve and putting a vacuum pump on it and . . . nothing. It can’t build or hold any vacuum inside the unit.
That’s kind of surprising as it’s an AC car with the vacuum line for the doors plumbed to a nipple on the check valve and the AC door vacuum pods all work fine. That and that the booster seems to do something when I start the motor had me thinking that everything was holding vacuum fine. But now it appears I’m just operating on manual brakes. I disconnected and capped the check valve vacuum nipple off to the AC while testing so all vacuum was applied to the booster only.
Sound right - I need a new booster?
I have a used booster I put on my 67 GTX years ago and it’s never seemed to do much as brake effort remains high. But since holding the brake pedal down while starting the engine causes it to drop a bit and then firm up, I figured it was working - at least somewhat. Finally I got around to pulling the hose on the check valve and putting a vacuum pump on it and . . . nothing. It can’t build or hold any vacuum inside the unit.
That’s kind of surprising as it’s an AC car with the vacuum line for the doors plumbed to a nipple on the check valve and the AC door vacuum pods all work fine. That and that the booster seems to do something when I start the motor had me thinking that everything was holding vacuum fine. But now it appears I’m just operating on manual brakes. I disconnected and capped the check valve vacuum nipple off to the AC while testing so all vacuum was applied to the booster only.
Sound right - I need a new booster?