77 Type LT ... In a rare instance of not having the the CD player going, at a stop light today I heard a faint sound, like sucking air. When I took my foot off the brake, the sound went away.. Press the brake, I hear it again. I am assuming there is leak in the booster... the cars does run a bit rough at cold start-up ... however, I see no degraded performance in the brake system... the pedal feels fine...Is there any way to detect a bad booster other than a stiff brake pedal...I am assuming that the car is running lean because of the rough cold idle ... maybe the booster is the cause ... I can't find a leak anywhere else and the carb ( rochester 2bbl ) was rebuilt a couple of months ago... I am asking because places I've check want to sell booster/master cyl together ... any and all suggestions would be welcomed and appreciated ... thanks in advance commendatiopn
What you are describing sounds like a bad booster.One way to check it is...start the car,let it run for a few minutes,then shut it off.Let it sit for 5 minutes,then pull the check valve off the booster.You should hear a rush of air.If not, make sure the check valve is good.If it's good,the booster is bad.