In my crx when I turn the car off I hear a hiss noise from around the brake booster. If I pull the vacuum line to the booster I no longer hear the hiss when I turn the car off. The car brakes fine when on and the pedal stays firm after a couple pumps with the car off.

Is my booster bad or could it be a seal between the MC and the booster or anywhere else? I'm just trying to get an idea of exactly what I need to buy because I don't have much money to play with.

The other thing that confused me was I pulled the booster off of my other car, and when you blow in it the air just comes out where the MC goes in. Even with the MC held on there is no change in resistance when blowing in. Shouldn't the booster hold that pressure when you blow into it?

 

the booster is going bad. When ever it starts hissing it means it is going bad. It will get worse till the point you will here it in the car when you are driving. I would replace it.

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