Hi all, first post and it's a plea for help, sorry!
Got me a 2005 C5 2.0 Hdi VTR - the facelifted version. Seems well looked after, 112k but serviced on the button every 20k miles.
Recently, whenever I start the car from cold (i.e. it's been lying for more than around 7 hours) the brakes won't work for anything between 30 seconds and two minutes. I need to sit with my foot on the pedal waiting on the system kicking in.
After this time, the pedal immediately loses it firmness - in other words, it doesn't slowly get softer, it just seems to come on all at once.
I understand the C5 has normal brakes not run off the suspension pump, so has anyone got any ideas?
C5 - brakes don't work after cold start
Moderator: RichardW
-
KevMayer
- Posts: 1051
- Joined: 12 Sep 2003, 22:01
- Location: Staffordshire, United Kingdom
- My Cars:
- x 2
The 'normal' brakes on the C5 are servo assisted and the servo gets it's vacuum from a small vacuum pump on the end of the camshaft. So, it could be a problem with either the vacuum pump or the servo.
Cheers, Kev
02 plate C5 2.2 Hdi Exclusive SE (now 170k miles 03/21).
Used to have:- Xantia 1.9 TurboD SX. 1996 Blue & 1998 Silver Activa. + 1992 BX TZD Turbo.
02 plate C5 2.2 Hdi Exclusive SE (now 170k miles 03/21).
Used to have:- Xantia 1.9 TurboD SX. 1996 Blue & 1998 Silver Activa. + 1992 BX TZD Turbo.
I had considered whether it was the vacuum pump or the servo, but the thing is, once the couple of minutes is up and they start working again, they're fine.
I'm absolutely not mechanically minded, but I did once have a little diesel 106 which had a problem with fuel running back into the tanks due to the fuel line having air getting into it somewhere. It was harder to start the longer it had been left as more and more air got into the lines.
So it got me to thinking, this problem is similar in that it's worse the longer the car is left. So whilst the vacuum pump might be fine, would I be right in suspecting that the vacuum system is a sealed system (even when the car is switched off), and if that seal were faulty somewhere, even a tiny leak, then the longer it was left, the more work the pump would have to do to recreate the vacuum state once the engine is started again?
I'm absolutely not mechanically minded, but I did once have a little diesel 106 which had a problem with fuel running back into the tanks due to the fuel line having air getting into it somewhere. It was harder to start the longer it had been left as more and more air got into the lines.
So it got me to thinking, this problem is similar in that it's worse the longer the car is left. So whilst the vacuum pump might be fine, would I be right in suspecting that the vacuum system is a sealed system (even when the car is switched off), and if that seal were faulty somewhere, even a tiny leak, then the longer it was left, the more work the pump would have to do to recreate the vacuum state once the engine is started again?
You should definately NOT loose the brakes function even with no vaccum.
The vacuum servo is only there to ASSIST you in decreasing the necessary foot pressure on the pedal.
It is in no way meant to supply the brakes forces by itself.
The method to check if the vacuum assist servo is functioning is as follows :
1) engine stopped handbrakes on.
2) press and HOLD the brakes pedal down
3) start engine and observe within a few seconds how the brakes pedal now sinks further down under your continued constant foot pressure. It should be a VERY clear feeling in your foot.
If this does not happen, your vacuum assist system is NON-functioning.
Further : with engine stopped, and any vacuum released by pumping the brakes pedal, you should still CLEARLY could brake down the car, if it rolls down your driveway.
If NOT, you have a VERY serious brakes fault.
The vacuum servo is only there to ASSIST you in decreasing the necessary foot pressure on the pedal.
It is in no way meant to supply the brakes forces by itself.
The method to check if the vacuum assist servo is functioning is as follows :
1) engine stopped handbrakes on.
2) press and HOLD the brakes pedal down
3) start engine and observe within a few seconds how the brakes pedal now sinks further down under your continued constant foot pressure. It should be a VERY clear feeling in your foot.
If this does not happen, your vacuum assist system is NON-functioning.
Further : with engine stopped, and any vacuum released by pumping the brakes pedal, you should still CLEARLY could brake down the car, if it rolls down your driveway.
If NOT, you have a VERY serious brakes fault.
Anders (DK) - '90 BX16Image
To clarify:
The brakes do always apply themselves to the wheels, but as mentioned above, if the car has been lying for more than around 6 hours, then it can take anything from a few seconds to about two minutes until the servo starts functioning.
Before that happens, it takes a very great deal of pressure on the pedal to stop the car from even the slowest of speeds if I were to drive off. The C5 is a heavy beast and definitely needs servo assistance to stop safely!
So I've learned to sit with my foot on the brake when I start the car, and wait until the pedal sinks before moving off. This happens all of a sudden, rather than gradually, so it seems that the problem is not with the servo, but with whatever activates the servo - I'm presuming the vacuum system?
The brakes do always apply themselves to the wheels, but as mentioned above, if the car has been lying for more than around 6 hours, then it can take anything from a few seconds to about two minutes until the servo starts functioning.
Before that happens, it takes a very great deal of pressure on the pedal to stop the car from even the slowest of speeds if I were to drive off. The C5 is a heavy beast and definitely needs servo assistance to stop safely!
So I've learned to sit with my foot on the brake when I start the car, and wait until the pedal sinks before moving off. This happens all of a sudden, rather than gradually, so it seems that the problem is not with the servo, but with whatever activates the servo - I'm presuming the vacuum system?
-
jonathan_dyane
- Posts: 229
- Joined: 10 May 2004, 23:32
- Location:
- My Cars:
I must confess I have no knowledge of the C5 braking system, but on most 'conventional set-ups' on a diesel, there is a vacuum pump which supplies the servo with vacuum via a flexible rubber hose, The first thing I would do would be to examine this hose, paying particular attention to where it passes through brackets and over metal work so as to discover whether it has chaffed so causing a leak.
Jonathan
1986 Mercedes Benz 190D 2.5
1979 GS 1220 Club Estate awaiting more welding
1952 David Brown 30D awaiting new liners
1986 Mercedes Benz 190D 2.5
1979 GS 1220 Club Estate awaiting more welding
1952 David Brown 30D awaiting new liners
Gary -
The standard vacuum servo test explained is very clear : the moment you start the engine the pedal MUST sink.
If not, you have a serious brakes fault.
If you are not mechanically minded, you should seek assistance ASAP at your garage.
It is by all means the most dangerous part of your car to have at fault
I agree with Jonathan :
A split vacuum feed hose may pull itself together when the vacuum is strong enough, giving you the rather strange sudden servo assist.
There is no definite answer to your problem, it must be fault traced.
The standard vacuum servo test explained is very clear : the moment you start the engine the pedal MUST sink.
If not, you have a serious brakes fault.
If you are not mechanically minded, you should seek assistance ASAP at your garage.
It is by all means the most dangerous part of your car to have at fault
I agree with Jonathan :
A split vacuum feed hose may pull itself together when the vacuum is strong enough, giving you the rather strange sudden servo assist.
There is no definite answer to your problem, it must be fault traced.
Anders (DK) - '90 BX16Image
Thanks for the advice folks, it sounds very probable that I'm looking at a fault with the vacuum system, then, either a split hose or a worn seal somewhere.
I just wanted a good idea of what it might be before booking it into the garage, I've been stung in the past with vague intermittent problems that the garage tries to solve by just replacing one expensive part after another, rather than attempting to properly diagnose what it is.
I shall book it in ASAP to a different garage with the specific instruction to thoroughly check the vacuum system. I've read about this problem a few times on various forums in my quest to solve this, but none has said what the solution was - if I get it solved, I'll post back in the hope that it helps others afflicted by it in the future!
I just wanted a good idea of what it might be before booking it into the garage, I've been stung in the past with vague intermittent problems that the garage tries to solve by just replacing one expensive part after another, rather than attempting to properly diagnose what it is.
I shall book it in ASAP to a different garage with the specific instruction to thoroughly check the vacuum system. I've read about this problem a few times on various forums in my quest to solve this, but none has said what the solution was - if I get it solved, I'll post back in the hope that it helps others afflicted by it in the future!
Hi GaryP
I agree with the other members that have replied that you have to work through the problem methodically, and look at the problem with these replies in mind to find the problem.
Has you car been in for a recall in the past, prior to you taking it on?
The reason why I ask is that there have been recalls issued for the C5, and several concern the brakes, they are listed on the V.O.S.A. website but it would seem one of them would only apply to your car looking at the year of it.
Here's the information from it listed below..................
Vehicle Details
Reference : R/2008/017
Manufacturer Ref : YER
Make: CITROEN
Model : C4 & C5
Launch Date : 05/02/2008
Numbers Involved : 520
Build Start Date : 06/07/2005
Build End Date : 07/07/2005
Recall Details
Concern : POSSIBILITY OF REDUCED BRAKING PERFORMANCE
Description : It has been identified that, vehicles fitted with 2I HDI engines may have been fitted a vacuum pump which may not be to specification. This could lead to a decrease in braking assistance.
Remedial Action : Recalled vehicles will have the vacuum pump replaced.
Vehicle Id : VF7**************[VIN obfuscated, can be read by forum staff]******76602542 to VF7**************[VIN obfuscated, can be read by forum staff]******76701556
VF7**************[VIN obfuscated, can be read by forum staff]******74299142 to VF7**************[VIN obfuscated, can be read by forum staff]******74459012
Please check your chassis number against the ones listed, to make sure that if the modification applies, that it has been done.
The link below shows the two pages that cover the C5, reading further, and depending when it was built, and sold, even this recall below might apply.
http://www.vosa.gov.uk/vosa/apps/recall ... search.asp
Vehicle Details
Reference : R/2004/096
Manufacturer Ref :
Make: CITROEN
Model : C5
Launch Date : 07/06/2004
Numbers Involved : 3562
Build Start Date : 01/02/2003
Build End Date : 31/03/2004
Recall Details
Concern : ENGINE MAY REVERT TO BACK UP MODE.BRAKE ASSISTANCE MAY REDUCE
Description : The original ECU software could generate an excessive vibration of the injection butterfly. In very rare cases the butterfly upper stop may fail causing the engine to go to back up mode which may result in a drop of brake assistance efficiency
Remedial Action : Recall affected vehicles and download new engine ECU software and initialisation of the ECU.
Vehicle Id : VF7**************[VIN obfuscated, can be read by forum staff]******76332962 to VF7**************[VIN obfuscated, can be read by forum staff]******76506174
I agree with the other members that have replied that you have to work through the problem methodically, and look at the problem with these replies in mind to find the problem.
Has you car been in for a recall in the past, prior to you taking it on?
The reason why I ask is that there have been recalls issued for the C5, and several concern the brakes, they are listed on the V.O.S.A. website but it would seem one of them would only apply to your car looking at the year of it.
Here's the information from it listed below..................
Vehicle Details
Reference : R/2008/017
Manufacturer Ref : YER
Make: CITROEN
Model : C4 & C5
Launch Date : 05/02/2008
Numbers Involved : 520
Build Start Date : 06/07/2005
Build End Date : 07/07/2005
Recall Details
Concern : POSSIBILITY OF REDUCED BRAKING PERFORMANCE
Description : It has been identified that, vehicles fitted with 2I HDI engines may have been fitted a vacuum pump which may not be to specification. This could lead to a decrease in braking assistance.
Remedial Action : Recalled vehicles will have the vacuum pump replaced.
Vehicle Id : VF7**************[VIN obfuscated, can be read by forum staff]******76602542 to VF7**************[VIN obfuscated, can be read by forum staff]******76701556
VF7**************[VIN obfuscated, can be read by forum staff]******74299142 to VF7**************[VIN obfuscated, can be read by forum staff]******74459012
Please check your chassis number against the ones listed, to make sure that if the modification applies, that it has been done.
The link below shows the two pages that cover the C5, reading further, and depending when it was built, and sold, even this recall below might apply.
http://www.vosa.gov.uk/vosa/apps/recall ... search.asp
Vehicle Details
Reference : R/2004/096
Manufacturer Ref :
Make: CITROEN
Model : C5
Launch Date : 07/06/2004
Numbers Involved : 3562
Build Start Date : 01/02/2003
Build End Date : 31/03/2004
Recall Details
Concern : ENGINE MAY REVERT TO BACK UP MODE.BRAKE ASSISTANCE MAY REDUCE
Description : The original ECU software could generate an excessive vibration of the injection butterfly. In very rare cases the butterfly upper stop may fail causing the engine to go to back up mode which may result in a drop of brake assistance efficiency
Remedial Action : Recall affected vehicles and download new engine ECU software and initialisation of the ECU.
Vehicle Id : VF7**************[VIN obfuscated, can be read by forum staff]******76332962 to VF7**************[VIN obfuscated, can be read by forum staff]******76506174
ACTIVA
The car that looks like a family car, but has special secret hidden abilities.
The car that looks like a family car, but has special secret hidden abilities.
Thanks very much for that, I had known about the recall for the brakes, but not that it was specifically related to the vacuum pump - interesting.
My car appears to have a later VIN , is there any possibility that it still may be the same fault though?
I guess I now really just need to get it into a Citroen dealer and give them all the info I now have, am just terrified of the bill it might lead to with no guarantee of success!
*EDIT*
Actually, I've just noticed that for the R/2008/17 recall, you've given two sets of VIN numbers, whereas the source I got the info from originally (the car-by-car breakdown on the Honest John website) only had one. And sure enough, my car's VIN falls in the range I hadn't seen before.
It also appears to fall within the range of VIN that the following recall applies to, but the build dates given are after mine - could that be a mistake? Either way, it looks like we may have a solution - both recall dates are in early 2008 when I suspect my car was in ownership limbo between the former lease finishing and it being disposed of via auction.
It was last serviced in November 07 at 100k miles before either of these recall dates. My first course of action now is a phone call to them tomorrow to see if they can ascertain whether any of these recalls were carried out on my car. If not, I'll be a bit disappointed my Citroen dealer didn't pick up on it when I had it in sometime around August 08 for the FAP to be replaced.
Reference : R/2008/051
Manufacturer Ref : YES
Make: CITROEN
Model : C4 & C5
Launch Date : 06/05/2008
Numbers Involved : 2557
Build Start Date : 31/03/2006
Build End Date : 03/01/2007
Concern : THE BRAKE PEDAL COULD BECOME STIFF THEREBY REDUCING BRAKING ASSISTANCE
Description : The brake pedal might feel stiff and the braking distances extended as a result of a defect in the vacuum pump.
Remedial Action : Recall the vehicles that are likely to be affected to replace the valve in the vacuum pump.
Vehicle Id : VF7**************[VIN obfuscated, can be read by forum staff]******74459011 to VF7**************[VIN obfuscated, can be read by forum staff]******76796753
VF7**************[VIN obfuscated, can be read by forum staff]******74459011 to VF7**************[VIN obfuscated, can be read by forum staff]******76796753
My car appears to have a later VIN , is there any possibility that it still may be the same fault though?
I guess I now really just need to get it into a Citroen dealer and give them all the info I now have, am just terrified of the bill it might lead to with no guarantee of success!
*EDIT*
Actually, I've just noticed that for the R/2008/17 recall, you've given two sets of VIN numbers, whereas the source I got the info from originally (the car-by-car breakdown on the Honest John website) only had one. And sure enough, my car's VIN falls in the range I hadn't seen before.
It also appears to fall within the range of VIN that the following recall applies to, but the build dates given are after mine - could that be a mistake? Either way, it looks like we may have a solution - both recall dates are in early 2008 when I suspect my car was in ownership limbo between the former lease finishing and it being disposed of via auction.
It was last serviced in November 07 at 100k miles before either of these recall dates. My first course of action now is a phone call to them tomorrow to see if they can ascertain whether any of these recalls were carried out on my car. If not, I'll be a bit disappointed my Citroen dealer didn't pick up on it when I had it in sometime around August 08 for the FAP to be replaced.
Reference : R/2008/051
Manufacturer Ref : YES
Make: CITROEN
Model : C4 & C5
Launch Date : 06/05/2008
Numbers Involved : 2557
Build Start Date : 31/03/2006
Build End Date : 03/01/2007
Concern : THE BRAKE PEDAL COULD BECOME STIFF THEREBY REDUCING BRAKING ASSISTANCE
Description : The brake pedal might feel stiff and the braking distances extended as a result of a defect in the vacuum pump.
Remedial Action : Recall the vehicles that are likely to be affected to replace the valve in the vacuum pump.
Vehicle Id : VF7**************[VIN obfuscated, can be read by forum staff]******74459011 to VF7**************[VIN obfuscated, can be read by forum staff]******76796753
VF7**************[VIN obfuscated, can be read by forum staff]******74459011 to VF7**************[VIN obfuscated, can be read by forum staff]******76796753
OK, called the main dealer today and they checked and said my car *isn't* noted as requiring that recall - but as far as I can see, it does going by VIN number, although I'm not sure of the build date - it was registered in Feb 05, though, which would suggest it's before any of the build dates in those recalls.
I've booked it in for a look anyway - if it does turn out to be the vacuum pump, would I have any recourse in pointing out that it seems too much of a coincidence not to be related to the recall it supposedly doesn't need?
I'll be taking along a print-out of the recalls from the VOSA site just to make them aware that I know of them. I suppose it could just be coincidence that my vacuum pump is faulty, but that may end up costing me a pretty penny!
I've booked it in for a look anyway - if it does turn out to be the vacuum pump, would I have any recourse in pointing out that it seems too much of a coincidence not to be related to the recall it supposedly doesn't need?
I'll be taking along a print-out of the recalls from the VOSA site just to make them aware that I know of them. I suppose it could just be coincidence that my vacuum pump is faulty, but that may end up costing me a pretty penny!
The information on the V.O.S.A. web site is as supplied by Citroen U.K.
It has to be correct, and any manufacturer has to supply full correct, and up to date information, as they are required to do so, by the agency, and the government.
Who did you speak to at the "main stealer?"
It has to be correct, and any manufacturer has to supply full correct, and up to date information, as they are required to do so, by the agency, and the government.
Who did you speak to at the "main stealer?"
ACTIVA
The car that looks like a family car, but has special secret hidden abilities.
The car that looks like a family car, but has special secret hidden abilities.
Hi GaryP
Has the car been into the main stealer yet?
Also the reason why I asked the previous question, in the post above, was to see if you managed to speak to anyone with a technical background, or even the warranty administrator.
Has the car been into the main stealer yet?
Also the reason why I asked the previous question, in the post above, was to see if you managed to speak to anyone with a technical background, or even the warranty administrator.
ACTIVA
The car that looks like a family car, but has special secret hidden abilities.
The car that looks like a family car, but has special secret hidden abilities.
Took it into main dealer on Friday for a look.
Picked it up Saturday. Guy dealing with me was, I think, a service manager. Well, at least, he wore a shirt and tie and was based in the service department!
He reported back that they'd had a look and were unsure why it wasn't behaving itself. This was exactly what I'd feared, I've a real fear of just replacing stuff in the hope it works, rather than definitely knowing what it is.
He says... wait for it..... they think it's the vacuum pump! Replacement would be 180 quid supplied and fitted (which I'll admit is far less than I was fearing, but then I'm a pessimist when it comes to these things!).
So what now? Should I just book it in and ask to keep the old one, so I have it as a spare or could sell it in the event it turns out not to be the problem?
I understand some problems, especially things that only happen very intermittently, might be hard to diagnose, but what other options do I have?
The recall situation seems to be a non-starter, due to the build dates on both being after my car was manufactured. Should I contact Citroen UK and ask for clarification?
*EDIT* No harm in doing so, I guess, so I've already emailed Citroen UK to ask them to explain why my VIN is amongst those in the recall notices but isn't apparently affected by it.
Picked it up Saturday. Guy dealing with me was, I think, a service manager. Well, at least, he wore a shirt and tie and was based in the service department!
He reported back that they'd had a look and were unsure why it wasn't behaving itself. This was exactly what I'd feared, I've a real fear of just replacing stuff in the hope it works, rather than definitely knowing what it is.
He says... wait for it..... they think it's the vacuum pump! Replacement would be 180 quid supplied and fitted (which I'll admit is far less than I was fearing, but then I'm a pessimist when it comes to these things!).
So what now? Should I just book it in and ask to keep the old one, so I have it as a spare or could sell it in the event it turns out not to be the problem?
I understand some problems, especially things that only happen very intermittently, might be hard to diagnose, but what other options do I have?
The recall situation seems to be a non-starter, due to the build dates on both being after my car was manufactured. Should I contact Citroen UK and ask for clarification?
*EDIT* No harm in doing so, I guess, so I've already emailed Citroen UK to ask them to explain why my VIN is amongst those in the recall notices but isn't apparently affected by it.