Hissing noise coming from pedal area

[Makavelee]

Any idea what this could be? It happens about 15 minutes into a journey, a distict hiss noise every 5 seconds. It'll stop if I even slightly press in the brake pedal.

Also another noise that worries me is a kind of whirring noise. When traveling more than say 60 mph if I remove my foot from the accelerator a whirring noise will come from the rear of the car. Again this stops if I put my foot back on the acel pedal

Any ideas?

2006 6.0 vxr btw.

[mv6]

Do you wear snakeskin shoes?...........Sorry!

[Wolfracer]

Whirring noise most likely to be the dif. They all do it apparently. Try slowing from say 70 and you should hear it as you approach 50 and then disappears below that. Hissing noise is more of a concern. Possibly servo related?

[LawrenceF]

Leaky booster?

[Makavelee]

Thanks for your replies. If the diff sound is normal then that's cool.

Back to the hissing. The best I can discribe it is train letting of steam as strange as that sounds, it's not particaularly loud but you can definatly hear it, like I say it's not constant it's in bursts of 5ish seconds and stops when you press the brake pedal. Once released it starts again. Iv still got 8 months network q warrenty left, worth getting checked out?

[Boosted LS1]

The hiss will probably be vacuum loss from the booster/brake servo. Check to see if any rubber pipes aren't attached properly or are slightly damaged. Is the noise coming from the pedal area or back of the plenum area assuming you can tell?

[behold81]

Boosted LS1 said:

The hiss will probably be vacuum loss from the booster/brake servo. Check to see if any rubber pipes aren't attached properly or are slightly damaged. Is the noise coming from the pedal area or back of the plenum area assuming you can tell?

Also is it louder in the car than from the engine bay. I believe the is a known issue with the servos.