Stiff BRAKES! help!

[Joe Rodriguez]

I just converted the brakes on my 1985 Buick Ttype from the power master to regular vacumn brakes and my brakes are super stiff? They did the work at a local shop and they tell me that I need an extra vacumn brake booster? What should I do they already bled the brakes a few times?

 

[novaderrik]

where is the hose from the booster getting it's vacuum? how much vacuum is it seeing at the booster?

 

[Joe Rodriguez]

From the intake manifold. I do not know how much vacumn it's getting?

 

[novaderrik]

if you don't have one, get a vacuum gauge and hook it up to the hose going to the booster. anything less than 15" or so and the booster will start to lose effectiveness.

 

[Joe Rodriguez]

Yes I believe it was right around 15 what else can we do?

 

[Pittsburghkid]

Do the brakes stop the car? Do they lock up easily? If you answer yes then no the firm feeling may just be the brakes working. Remember the powermaster brake system is junk and over time it will wear down slowly without you noticing it. So when you get your brakes working again the way they should they can feel firm compared to the way they were. Also if the new booster is pushing more psi through the lines than before the proportioning vavle could be malfunctioning. Three different companies made the prop valves and only one was made from brass and the ones on the canadian cars were recalled. I did a search for you and this thread may help and if not the people in that thread should be able to.

http://www.turbobuick.com/forums/general-turbo-buick-tech/340518-powermaster.html

 

[1quick6]

I assume the check valve to the booster is good?

 

[Dukesie79]

Second that. I've seen them put in backwards in other cars and its almost impossible to depress the pedal and it doesn't stop very well at all.

 

[novaderrik]

how do you put the check valve in backwards?
one side is big enough to fit snugly in the grommet in the booster, and the other side has a 3/8" nipple on it.

 

[Dukesie79]

Sorry haven't actually seen it on our cars, just on others.

 

[Casey Jensen]

Ever considered changing to hydroboost? My brakes on my 84 gn work very well with no problems.