Hi Guys...here's the problem of the week!!!...OK the car is a 2007 C5 HDi BiTurbo and I have a fractured hydraulic pipe - looking at the car from the front ie. battery on right, the pipe that is connected to the left hand sphere and then runs down the bulkhead behind the left hand side of the engine in combination with 2 other hydraulic pipes making a 3 pipe combined unit (PSA part No: 5270RN)...no problem is replacing or repairing pipe...BUT...
I cannot access a Citroen dealer - don't ask!! - and I need my regular mechanic to replace or repair the pipe...BUT...I need to pressure down the hydraulic system WITHOUT using the computer...
My question is: How do you de-pressurise the system without using the computer to open all the ports??...and then when the pipe is fixed; How do you bleed the system WITHOUT using the computer to open all the ports??...Any help most gratefully received...thanx a mill dizzy...PS any hints or tips on extracting the pipe combo would be gratefully received as well...!!!
De-Pressurising the C5 Hydraulic system WITHOUT a computer??
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dizzyblond
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This is a "facelift" C5, right? Behind the front, right-hand headlight in the engine compartment, there will be a large relay. Probably brown in colour. Don't disconnect the battery - not needed.
You need to unplug the relay, as it supplies power to the pump.
I suggest then cracking the pipe nuts for each feed line, you will need to work patiently, in axle pairs. Unless the fluid is new-ish, discard once drained (measure the volume drawn out).
With a few cyclings of suspension the air will eventually purge upon reassembly.
You need to unplug the relay, as it supplies power to the pump.
I suggest then cracking the pipe nuts for each feed line, you will need to work patiently, in axle pairs. Unless the fluid is new-ish, discard once drained (measure the volume drawn out).
With a few cyclings of suspension the air will eventually purge upon reassembly.
Re: De-Pressurising the C5 Hydraulic system WITHOUT a comput
The fractured pipe will depressurise it for you. Without a fractured pipe, simple way is to drop the car to its lowest setting then jack the car. This causes the valves to stay open as the height sensors read that the car is high and the low position is selected. Then disconnect the battery.
As regards pressurising and bleeding the system a large amount of superstition has grown up. After repairs are effected and the battery is reconnected the pump starts and usually primes itself after a minute or so at most. On the very rare occasion that it fails to prime applying a small amount of pressure using something like Gunsons easi-bleed usually gets it going.
As regards bleeding the system to remove air two or 3 cycles of raising the car to maximum and then lowering it to minimum using the buttons in the centre console will do the trick. Any remaining air will work its way out in normal driving.
The hydraulic reservoir is normally kept under a slight positive pressure. This is a trick Citroën recently learned. It has been used for years on trucks with cranes (like HiAb) and a lot of construction machinery. It has nothing to do with the operation of the system but is in order to stop air being changed in the reservoir. Each change of air brings with it water vapour. This vapour may condense into the fluid causing deterioration of the fluid and corrosion of the working parts. An occasional change does no harm but on an unpressurised system the air may be expelled and fresh air drawn several times per hour as the system is working. The pressurised reservoir and the change to LDS fluid allowed the recommended fluid life to be doubled.
To pressurise the reservoir first of all make sure that you have the correct amount of fluid on the reservoir. Raise the car to maximum height preferably with a substantial load in the car. Remove and then tightly replace the reservoir cap. Lower the car to normal. Job done.
Edit: instead of disconnecting the battery you could unplug the relay as described above by Ado. We must have been typing at the same time.
As regards pressurising and bleeding the system a large amount of superstition has grown up. After repairs are effected and the battery is reconnected the pump starts and usually primes itself after a minute or so at most. On the very rare occasion that it fails to prime applying a small amount of pressure using something like Gunsons easi-bleed usually gets it going.
As regards bleeding the system to remove air two or 3 cycles of raising the car to maximum and then lowering it to minimum using the buttons in the centre console will do the trick. Any remaining air will work its way out in normal driving.
The hydraulic reservoir is normally kept under a slight positive pressure. This is a trick Citroën recently learned. It has been used for years on trucks with cranes (like HiAb) and a lot of construction machinery. It has nothing to do with the operation of the system but is in order to stop air being changed in the reservoir. Each change of air brings with it water vapour. This vapour may condense into the fluid causing deterioration of the fluid and corrosion of the working parts. An occasional change does no harm but on an unpressurised system the air may be expelled and fresh air drawn several times per hour as the system is working. The pressurised reservoir and the change to LDS fluid allowed the recommended fluid life to be doubled.
To pressurise the reservoir first of all make sure that you have the correct amount of fluid on the reservoir. Raise the car to maximum height preferably with a substantial load in the car. Remove and then tightly replace the reservoir cap. Lower the car to normal. Job done.
Edit: instead of disconnecting the battery you could unplug the relay as described above by Ado. We must have been typing at the same time.
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dizzyblond
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Re: De-Pressurising the C5 Hydraulic system WITHOUT a comput
Heh Guys - 'addo' and 'BX' - that is awesome, thank you and thank you again...as the car has been sitting in one spot for the last 6 weeks and the suspension (on high setting) has NOT collapsed I am assuming that the leak that I have is NOT from the larger (diameter) of the pressurised pipes that originates from behind the sphere??...I am assuming that it is from one of the other 2 pipes in the assembly (of 3 pipes that runs down the bulkhead) and I am further assuming that these pipes are simple fluid return pipes and not under huge pressure...anyone care to comment on my list of assumptions and explain exactly how I am making an 'Ass of U and Me' !!!...also has anyone had any experience of actually taking one of these 3 pipe assemblies off the car??...that's about it, thanx for all your help again, wish me luck...kind regards dizzy
Re: De-Pressurising the C5 Hydraulic system WITHOUT a comput
I replaced all the pipes going to the rear of a c5 about 10years ago. That is fuel, suspension brakes and exhaust. The car was after having an unplanned cross country experience. The brake pipes were standard and I just replaced the damaged sections. I cannot remember what I did with the suspension pipes. What you are saying seems to make sense. Don't forget that the power steering uses LDS fluid from the same reservoir even though otherwise it is not linked to the suspension system. The brakes are totally separate and use brake fluid. If you trace the pipes you may see where they come from or if you can get a picture and post it someone may be able to help.
Re: De-Pressurising the C5 Hydraulic system WITHOUT a comput
If we're thinking of the same pipe 'loom' here one of the pipes goes to the steering rack aswel ? Is it hydractive 3+ ?
If it's that same lot of pipes & it's the same as a mk1 then drop the front subframe, it will save you a whole load of time & hassle, the first time I done this job I done it without dropping the subframe & it was a nightmare, the pipes came out easy enough but was a nightmare to get the new ones back in.
For future ref, to fully depressurise without lexia drop it in low then open the nipples on each of the stiffness regulators on each axle till the fluid stops.
If it's that same lot of pipes & it's the same as a mk1 then drop the front subframe, it will save you a whole load of time & hassle, the first time I done this job I done it without dropping the subframe & it was a nightmare, the pipes came out easy enough but was a nightmare to get the new ones back in.
For future ref, to fully depressurise without lexia drop it in low then open the nipples on each of the stiffness regulators on each axle till the fluid stops.
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dizzyblond
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Re: De-Pressurising the C5 Hydraulic system WITHOUT a comput
Heh 'addo' it is a facelift C5...BUT...I tried to find the relay you mentioned today but it not there!! well I couldn't locate it more like!!...would it do the same job if I just disconnected the plug from the pump - that is the 'pump' under the LDS container, right??...failing that I may have to disconnect the battery but I seem to recall that there is some sort of procedure for doing this, yes/no??...thanx 'bx' I thought one of the 3 pipes was connected to the steering rack, which all starts to make sense as the event that precipitated this minor nightmare was discovering that the steering rack was very loose - floating around enjoying it's new found freedom, courtesy of a major Citroen dealer!! - and so my bet is that the fractured pipe is the one feeding the rack...and good to know about dropping the the subframe, thanx 'wheeler' but tell me where exactly are the 'stiffness regulator nipples'...thanx again guys all this is really appreciated...btw 'addo' I'm in NSW as well might be an idea to get you number if that's cool??...kind regards dizzy
Re: De-Pressurising the C5 Hydraulic system WITHOUT a comput
Yes, the plug with the 2 heavy wires.
There are drain nipples under the car. They look like brake bleed nipples. On c5s with "standard" hydractive 3, there one at the front an one at the rear on the middle. You don't need to worry about them. Lower the suspensions, disconnect the pump and jack the car and the pressure will be gone to the extent that you can work on the pipes or anything else on the suspension.
There are drain nipples under the car. They look like brake bleed nipples. On c5s with "standard" hydractive 3, there one at the front an one at the rear on the middle. You don't need to worry about them. Lower the suspensions, disconnect the pump and jack the car and the pressure will be gone to the extent that you can work on the pipes or anything else on the suspension.