Brake Pedal Hissing Noise

[Eric breeds]

Hi my 2001 galaxy 2.3 auto has a air hissing noise at the brake pedal it stops when pressed and stars when you take foot off the brake but the brakes work very well no problems at all so hopeing it don't need a new master cylinder so hopeing someone might of had this problem before to tell me what it is or what to check

[BrianH]

Hi my 2001 galaxy 2.3 auto has a air hissing noise at the brake pedal it stops when pressed and stars when you take foot off the brake but the brakes work very well no problems at all so hopeing it don't need a new master cylinder so hopeing someone might of had this problem before to tell me what it is or what to check

Sounds like a leaking servo - theres a seal on the back that you can see from underneath. If its not causing problems with the brakes you'd probabbly best leave it alone as getting a replacement servo isn't particually straightforward, a second hand one may be just as bad, new ones you need the right one for your vehicle, as they differ between lefthand and righthand drive, and the master cylinder.

 

Mine did it for some time, i ended up putting some grease on the seal which seems to have stopped it.

[Eric breeds]

Might try that how do I get to the seal please

[BrianH]

Might try that how do I get to the seal please

You can see it from the footwell under the console on the mk1, your mk2 you may have to remove the lower panel to see it, but have a look underneath there - its all accessible from the pedal end.

 

The other thing that can happen is the feed into the servo splits - this would be under the bonnet, its a rigid plastic hose that feeds into the servo from the inlet manifold.