Hissing noise
 

My 1998 Grand Voyager has developed a persistant hissing noise when the brake pedal is released - it continues until the pedal is depresed again - the sound appears to be coming from behind the centre console at floor level.

Any help would be appreciated

Thanks

RE: Hissing noise
 

Sounds like you have a leak in your power brake booster. disconnect it from the vaccum source under the hood by removing the large vacuum line and plug the line with a bit of duct tape. then start the car, go in and press on the brake and see if you still hear the hiss. if no, then brake booster is likely defective, if you still hear it, check around the brake pedal to make sure none of the vacuum line running to the HVAC system have come pinched or brokenand get moved with the action of the pedal. make sure you reconnect the brakebooster before trying to drive it. They are mighty hard to stop without that booster!

-JErry

RE: Hissing noise
 

Thanks Jerry,

Will do as you suggested and let you know the outcome.

RE: Hissing noise
 

Jerry,

Is the brake booster situated behind a small black plastic cover in the passenger footwell? - that is where the hissing is comming from - took the cover off and when the assembly is pushed in the noise stops the starts again when released - is the unit easy to replace and is it dangerous to drive in current condition?

Thanks

RE: Hissing noise
 

Hi Is yours a right hand drive? Sounds like the brake booster/servo. Not nice to change.

RE: Hissing noise
 

Yes it's right hand drive - can't be any worse than replacing the rear set of spark plugs?

RE: Hissing noise
 

The brake booster is under the hood directly behind the brake pedal. I do not know how a right hand drive is set up but I would think it would be relocated to the drivers side of the vehicle. either way, you cannot get to it from inside the car except perhaps if there is a linkage that connects the break peddle on the right to the booster mounted on the left.

When you open the hood and check the brake fluid, where (on which side) is the reservoir? as it is generally mounted on the break booster atop the master cylinder.

RE: Hissing noise
 

Wow, my spelling sucks!!!! make that "brake pedal" and "brake booster" ;-)

RE: Hissing noise
 

hi i had same fault, the rubber on the end of the brake servo needed pushing back into the retaining clamp, this is right up under the glove box try pushing and twisting this rubber tube thing.

Mick

RE: Hissing noise
 

Yes it is harder then the rear spark plugs. The right hard drive have a linkage going behind the heater to the brake servo it the passenger footwell. You can get to the linkage and the 4 nuts that hold the servo in from the foot well. Then it’s just remove the master cylinder and the servo comes away. Long time since I did one but think I had to remove the top half of the inlet manifold or the throttle body as the servo was just too big to get out. The EGR pipe to the exhaust is a pain too.