[gary91799]

HI have a t4 2.5 tdi 2000 model with a hissing noise coming from brake area, stops when you push down, someone has mentioned that servo is on its way out or a rubber seal can be replaced to rectify the hiss?
The hiss has been annoying me for 7 mths and its about time to sort out.
cheers

 

[T4 cookie]

Hi, im interested in this had exactly the same thing two weeks ago but now stopped ?

 

[gary91799]

Yeah mine is intermittent as well,

hopefully someone has sollution

 

[nasty nick]

apparently its a non serviceable part, mines the same.
Its around £280 for the servo + fitting for mine

 

[gary91799]

cheers for reply

 

[hobbyhorse]

Some people here will tell you that greasing the servo shaft ( inside the bellows ) is a cure - it isn't, it's a bodge & it just leaks quietly afterwards. ( hissing servo is an MOT fail )
The servo is quite tricky to change on a short nose 2.5 tdi - it jams between the screen wiper mech & the dipstick tube; thankfully the new replacement part is slightly smaller; I would recommend changing the master cylinder while you've got it in in pieces T:

 

[Endorphinix]

Just bought one with this fault too. was fine on test drive and then SSSSSSSSSS when i braked hard 1/4 mile from home after a 100 mile journey. Thought it'd been silently overheating then blown or i'd had a blow out..
I read another thread that said to wrap insulating tape around end of that grey baffle behind pedal. I pressed the seal as hard as i could then secured with little tape. Very temp fix though as going to garage next thursday.
Let me lknow your outcome,
cheers

 

[AndyGG]

I replaced mine with one from a scappy...quite an easy job. £60 for the part...you can just unbolt the master cylinder and squeeze the servo past (carefully). Sure there's a guide on here somewhere.

 

[AndyGG]

http://www.vwt4forum.co.uk/showthread.php?t=140787