Under dash hissing noise

2008 HHR, Had heard hissing noise like a vacuum leak while releasing brake pedal, now there's a constant hissing noise coming from under the dash above the brake pedal. No changes noticed in performance. Having trouble pinning this down- can anyone help?

2008 HHR, Had heard hissing noise like a vacuum leak while releasing brake pedal, now there's a constant hissing noise coming from under the dash above the brake pedal. No changes noticed in performance. Having trouble pinning this down- can anyone help?

Hissing noise? Not good. Have you been able to take it to the dealer yet? I can set up an appointment if you would like.

Erica
Chevrolet Customer Service

Classic vacuum brake booster leak at seal- needs replaced- engine is sucking in extra air- not good for gas mileage either.

Thanks for the quick replies. @ brcidd- Is there any way to verify it's gone? Do the master cylinder lines have to be broken? @ Erica- Appreciated, but no thanks, dealerships never come cheap.

If there is plenty of room- it is a cake walk....master cylinder just unbolts from front- no need to unhook brake lines- and there are four bolts under dash and of course, brake pedal linkage- I've done 5 or 6 but never on an HHR- can be a pricey part- $120 or so- and they want a core...all depends on how much room there is to work it out.....

Just took a look under the hood, of course there's no room, it's tucked under the firewall with a buttload of things in the way.:moppie: Of course the part is going to cost me $200 because I have the active brake control, labor is going to kill me. Thaks so much for your help- have a happy Easter.