is my brake booster bad?

[C928BRAN]

when i start the car, it will pull the brake pedal down, and when i turn the car off, the pedal will come back up. is my booster bad?

thanks, craig

[Rolling_Thunder]

put light pressure on the pedal with the car off - when you start the car the pedal should move down slightly (1/2" or so) - this shows that the booster is working normally - with the engine off the pedal will return to the higher up position  

[b5blue]

Somethings wrong, mine never did that. 

[bobs66440]

put light pressure on the pedal with the car off - when you start the car the pedal should move down slightly (1/2" or so) - this shows that the booster is working normally - with the engine off the pedal will return to the higher up position   

I agree. On all my cars with power brakes, the pedal drops a bit when started, but I never noticed it come back up when shut off. But then again, I never looked for it. 

[C928BRAN]

it will go down, but wont come back up untill the car is shut off. i noticed the brake lights were on, and then i shut the car off, and they went off. while the car is running, its like pushing against a brick wall, no movement at all. everything is brand new on the car, except for the booster. if any body has a booster, that they know is good, i would buy it. i have a 1969 dodge charger, origianly, power drum, now disc on front.

thanks, craig

[FLG]

Bad valve inside the booster, replace it or send it out to be rebuilt...from what i remember this guy is good

http://boosterdeweyexchange.com/

If you need to move the car you can unhook the vac line going tho the booster...do not drive the car around like this..stopping well be very difficult. If you remove the line make sure you plug it (small bolt  on the line will do)

[Back N Black]

it will go down, but wont come back up untill the car is shut off. i noticed the brake lights were on, and then i shut the car off, and they went off. while the car is running, its like pushing against a brick wall, no movement at all. everything is brand new on the car, except for the booster. if any body has a booster, that they know is good, i would buy it. i have a 1969 dodge charger, origianly, power drum, now disc on front.

thanks, craig

Are you using the drum brake booster on the new disc brake setup? The boosters are different, the disc brake booster is 2 inches deeper and has a double diaphragm . Some guys seem not to have issues with interchange. Maybe something to look into.

[Dino]

it will go down, but wont come back up untill the car is shut off. i noticed the brake lights were on, and then i shut the car off, and they went off. while the car is running, its like pushing against a brick wall, no movement at all. everything is brand new on the car, except for the booster. if any body has a booster, that they know is good, i would buy it. i have a 1969 dodge charger, origianly, power drum, now disc on front.

thanks, craig

Are you using the drum brake booster on the new disc brake setup? The boosters are different, the disc brake booster is 2 inches deeper and has a double diaphragm . Some guys seem not to have issues with interchange. Maybe something to look into.

I'm wondering about that myself.  I spoke to a few guys that said the drum booster should work fine when you install front discs, and I will find out soon enough, but I'm prepared to buy a new disc booster!

[C928BRAN]

My car was origianly power drum, and i put on disc, with a disc master cylinder. from what the guy told me at the parts store, from drum to disc were definently different, so i ordered the disc booster, and he told me it was the only one the system showed to have. he told me if i didnt get this one, he wasnt even sure he would be able to get one later on, so i bought it. hope this fixes my problem, because everything else is new.

craig