S60 Brakes: - Brake vacuum servo unit 'screeching'

TylerWatts · Feb 20th, 2012, 20:03

Hello guys

I'm getting a strange varying noise from my brakes at the pedal, ranging from a 'windy' sucking sound to a wheezing to a screeching sound at times when the brake pedal is released. If the pedal is touched just slightly when the noise is being made it stops. It is not a consistent sound, nor does it change with engine speed (I would expect the vacuum to vary with varying revs).

I can only assume it is the Vacuum servo Unit between the pedal and master cylinder, and that the master cylinder actuator shaft has a seal on it to maintain the vacuum in the Vacuum Servo Unit that is now leaking air and causing the noise. My mrs has also noticed reduced braking assistance (greater effort to stop) which has caught her out quite a few times now and is of concern.

Does anyone have any input/guidance to this please, or any suggestion where to get a replacement Vacuum Servo Unit please. Also, Haynes instructs dropping the whole subframe and drive train few inches to get the Servo Unit out, is this really necessary? I hope I don't ever meet a Volvo Engineer, he'll be agressively re-educated on the subject of "Design for Service".

Thanks in advance for your assistance!
Tyler

outnumbered · Feb 20th, 2012, 20:32

did you get the other issues sorted the EGR and the MAF .
mike

TylerWatts · Feb 21st, 2012, 07:54

Hi Mike
Not quite (see pm), but it was greatly improved following your assistance, thank you. been occuring more so again recently though, but not alot, and not enough yet to cause serious concern. Seemed more like false neutrals with second gear of late.

Anyone able to offer any response to my original post please?

Thanks

spokoluzik · Feb 21st, 2012, 09:19

Any part number??
Is dstc or stc car??

TylerWatts · Feb 21st, 2012, 09:58

spokoluzik

I do not understand the second question, sorry, and have not got a part number as I cannot get the the servo unit without removing it. Not called Volvo to ask. Car is 02 S60 D5.

spokoluzik · Feb 21st, 2012, 10:30

Traction button on dashboard says dstc or stc??

TylerWatts · Feb 21st, 2012, 10:53

I believe from memory it is STC, but not 100% sure, and it is located next to hand brake, not dash.

Simon Jones · Feb 22nd, 2012, 00:04

Does sound like the servo is on its way out. The subframe does have to be lowered to gain access and I seem to recall a price quoted of over £300 just for the parts.

Feb 20th, 2012, 20:03	#1
TylerWatts Junior Member Last Online: Apr 29th, 2016 08:26 Join Date: Mar 2010 Location: Derby	Brake vacuum servo unit 'screeching' Hello guys I'm getting a strange varying noise from my brakes at the pedal, ranging from a 'windy' sucking sound to a wheezing to a screeching sound at times when the brake pedal is released. If the pedal is touched just slightly when the noise is being made it stops. It is not a consistent sound, nor does it change with engine speed (I would expect the vacuum to vary with varying revs). I can only assume it is the Vacuum servo Unit between the pedal and master cylinder, and that the master cylinder actuator shaft has a seal on it to maintain the vacuum in the Vacuum Servo Unit that is now leaking air and causing the noise. My mrs has also noticed reduced braking assistance (greater effort to stop) which has caught her out quite a few times now and is of concern. Does anyone have any input/guidance to this please, or any suggestion where to get a replacement Vacuum Servo Unit please. Also, Haynes instructs dropping the whole subframe and drive train few inches to get the Servo Unit out, is this really necessary? I hope I don't ever meet a Volvo Engineer, he'll be agressively re-educated on the subject of "Design for Service". Thanks in advance for your assistance! Tyler

Feb 20th, 2012, 20:32	#2
outnumbered Lunatic from Wakefield Last Online: Apr 16th, 2023 06:33 Join Date: Dec 2004 Location: wakefield	did you get the other issues sorted the EGR and the MAF . mike __________________ 2012 volvo xc90 Executive Buccaneer Bermuda 2021

Feb 21st, 2012, 09:19	#4
spokoluzik Trader Last Online: Dec 6th, 2023 19:46 Join Date: Jun 2010 Location: london	Any part number?? Is dstc or stc car?? __________________ http://volvodiagnostic.com/

Feb 21st, 2012, 10:30	#6
spokoluzik Trader Last Online: Dec 6th, 2023 19:46 Join Date: Jun 2010 Location: london	Traction button on dashboard says dstc or stc?? __________________ http://volvodiagnostic.com/

Feb 21st, 2012, 07:54	#3
TylerWatts Junior Member Last Online: Apr 29th, 2016 08:26 Join Date: Mar 2010 Location: Derby	Hi Mike Not quite (see pm), but it was greatly improved following your assistance, thank you. been occuring more so again recently though, but not alot, and not enough yet to cause serious concern. Seemed more like false neutrals with second gear of late. Anyone able to offer any response to my original post please? Thanks

Feb 21st, 2012, 09:58	#5
TylerWatts Junior Member Last Online: Apr 29th, 2016 08:26 Join Date: Mar 2010 Location: Derby	spokoluzik I do not understand the second question, sorry, and have not got a part number as I cannot get the the servo unit without removing it. Not called Volvo to ask. Car is 02 S60 D5.

Feb 21st, 2012, 10:53	#7
TylerWatts Junior Member Last Online: Apr 29th, 2016 08:26 Join Date: Mar 2010 Location: Derby	I believe from memory it is STC, but not 100% sure, and it is located next to hand brake, not dash.

Feb 22nd, 2012, 00:04	#8
Simon Jones Premier Member Last Online: Jan 15th, 2022 11:23 Join Date: Feb 2009 Location: Salisbury (ish)	Does sound like the servo is on its way out. The subframe does have to be lowered to gain access and I seem to recall a price quoted of over £300 just for the parts.

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