no brakes under boost? until it goes to vacuum?

[jasonlee]

well, here is the problem...

when i am boosting, above like say 8 or 10 psi... then i have to brake quick... there is nooo brakes for like a second... until the psi drops to vacuum...

the pedal is really hard to push until it goes vacuum....

and if my foot is on the brake pedal lightly when i start to boost,... i feel the brake pedal come up... pushing my foot up


is this at all normal??

j

 

[Lordpaxin]

your cars "power" assisted brakes run off vacuum.

the vacuum is supplied by a rubber hose running from the back of the intake manifold to the brake master.

this hose has a 1way check valve designed to block incomming PSI air so the inside if the master is still at vacuum under boost. and at vacuum, the valve is pulled open by the vacuum.

sounds to me you either replaced the hose and didnt add the valve, or your vavle is faulty.

 

[Defiant]

^ ^ ^ Yes- and unlike many cars, the check valve in DSMs is hidden inside the vacuum hose.

 

[jasonlee]

ahh haaa!!! thats it! thanks guys!! i did replace the hose... i didnt know that there was a check valve inside there!!

this site rocks...


major thanks to everybody

j

 

[Lordpaxin]

Excellent,
It feels good to help another tuner figure out a problem.
thats the purpose of the site