I have a hiss coming from under the dash after I step on the brake pedal and the pedal is released. Stepping on the pedal stops the hiss. There is no loss of brake response or action. This happensboth while the vehicle is in motion and while it isstationary. I can turn off the vehicle and the hiss continues. I have not been able to verify that it continues after the vehicle has sat awhile. Again, if you step on the brake pedal the hiss stops and may or may not start again.
Thanks for your help.

 

Your brake booster is bad and it needs to be replaced. It very common on the S80.

ood Luck,

3B

 

I was kinda afraid of that. I'm used to Chevy style booster problems, not Volvo. Saying that is it a 1 banana , 2 banana or larger problem. (can a monkey like me do the replacement at home?)

Ok, I went back and found that the sticky above is for a brake booster replacement, however it is the same one as for a V70. Is that correct? How hard is it to remove the under dash stuff. I've always found dash removal the hardest.

Thanks again. Buzz

 

It is very similar if the V70 is a 2001- vehicle.

It makes a difference if you have a turbo or not. The turbo cars are a bit more involved.

I just checked out the sticky, it is correct, but an S80 may have some more stuff in the engine area to remove to get the booter out.

3B