View Full Version : hissing sid of a servo :smirk:

Wednesday 13th April 2005, 21:10
:smirk: I need some help if anyone can please.
I have just bought an auto t5 v70 MK2, i took it for a wee spin just 195 miles, when i noticed a sucking/hissing noise whilst stood still with the handbrake on, not a problem i thought my colostomy was full as i was having sooo much fun, i checked and it wasn't me. :yikes:

I then braked in order to remove the H BRAKE and the hissing ceased :rolleyes: i deduced that the problem was something to do with the brakes, i am not experiencing loss of pressure that i can notice, or fluid loss and the brakes feel fine, but the noise is really loud, it appears to come from the pedal box area under the dash not under the engine bay, i then had a bit of a mess and if you just touch the pedal very gently the noise ceases but returns upon acceleration, but quieter, more of a suck like a K and N i am truly mystifed, worried :saint:
If it is a servo master cylinder or padal box fault is it hard/pricey to fix :cry:

Wednesday 13th April 2005, 22:54
If you want to check a servo is working then....
Ignition off...pump brake pedal furiouslt until u feel pressure build up, then hold it,,,,turn ignition on, start and pedal should then drop slightly.
Sounds like you have a leak somewhere.
The servo works on engine vaccum (thats why the brakes are cr@p when the engine is not running) so if you have no vaccum you have no servo assistanvce.
Worst scenario....servo diagphram...best...leaky hose.
Try the servo test, if thats OK then a hose is probably the culprit.