brake problem

[cerryblazer]

Hello guys!
i have a problem with my ' 81 k5 Chevy Blazer, could you help me???
when i push down brake pedal, i hear a sound of air come out.
could be a brake booster leak?
thanks guys!
Fabio

 

[dyeager535]

Hello guys!
i have a problem with my ' 81 k5 Chevy Blazer, could you help me???
when i push down brake pedal, i hear a sound of air come out.
could be a brake booster leak?
thanks guys!
Fabio

GM simple brake booster test: Start truck, don't touch the brake pedal. Let it run for about a minute. Turn off truck. Wait one hour. Without starting vehicle, depress brake pedal. Should get 2-3 FULL pedal assists before it starts to fade.

 

[cerryblazer]

ok cool test!
thanks
so there is a problem with brake booster if i pushing down brake pedal, it is hard fro 2-3 time and then it starts to fade?
correct
thanks again!

 

[70jimmy]

First check and make sure the rubber grommet on the front of the booster is not leaking or torn. I have replaced two of these. cheap to do and sometimes overlooked.

 

[dyeager535]

ok cool test!
thanks
so there is a problem with brake booster if i pushing down brake pedal, it is hard fro 2-3 time and then it starts to fade?
correct
thanks again!

If the booster is leaking, by the one hour mark, the pedal should be hard as soon as you try to push it. You can do the same thing if you drive the truck, then turn it off and push the brake pedal a few times. Should be very easy for a few pushes, then get very hard.

 

[dyeager535]

Let me rephrase that...you can get an idea of how it will feel if the booster is bad by pushing on the pedal after shutting the truck off. The first couple of times it should feel just like when you are driving, after that it should be very difficult to push.

 

[cerryblazer]

hey guys thank you very much for help!
great explanation, i don't remember and i can't try now, but i think that brake pedal fades always! turn on or turn off!
mah! i'll try later and i will tell you
thanks!