MK5 Golf GTI

All Things Mk5 => Modifications & Technical Area => Technical Workshop => Topic started by: pudding on March 27, 2015, 11:08:31 am

Title: Hissing brake servo
Post by: pudding on March 27, 2015, 11:08:31 am

I understand a leaking brake servo is quite common the MK5 / 8P Audi A3, which causes an annoying hissing sound from the pedal area at low speeds and when idling.

Has anyone swapped the servo out themselves, or is it a ramp job because the engine has to be moved around a bit to get it out?

Title: Re: Hissing brake servo
Post by: bacillus on March 27, 2015, 05:31:03 pm

Usually it's a perished vacuum pump hose (as seen in the pic) that leaking and needs changing. Ignore the red circle in that pic.

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2FMatt_Bateson%2FMobile_Uploads%2Fimage_2.jpg&hash=e23624f731f53d0ee2437c5650e58652b83441a0)

Title: Re: Hissing brake servo
Post by: scopes on October 22, 2015, 01:59:30 pm

What is that nipple for on the hose that is marked with a red circle around it ???

Title: Re: Hissing brake servo
Post by: bacillus on October 23, 2015, 06:09:59 pm

Quote from: scopes on October 22, 2015, 01:59:30 pm

What is that nipple for on the hose that is marked with a red circle around it ???

On a mk5, vw has a block off rubber piece for that nipple as the original earlier ones didn't have it.
As for why it's there, haven't got a clue...

Title: Re: Hissing brake servo
Post by: GTI07 on October 28, 2024, 09:00:52 pm

Hi does anyone know if a hissing servo will cause clutch pedal to drop now and again or not ? I’ve had new clutch flywheel slave cylinder and had it bled twice to make sure wasn’t just air some people say it’s my clutch. Master but some say hissing servo will cause it only drop like once every few days then is fine again get stuck like half way coming back up ?? Any help appreciate jt