Citroen C5 control arm replacement

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Frosty1966

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Tadpole
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Hi can anyone supply me with advice when changing the control arms on my Citroen C5 do I need to set suspension at full height before I replace them? It's a 2009 C5 x7
 
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No, the system needs to be at ride height when you tighten up the bolts through the rubber bushes so there is no twist in them and the twist is then evenly distributed each way between up and down suspension exertions.

Also check the three bolts holding the bottom ball joint of the swivel are tight. Use locktite if you ever take them out and don't replace them as advised by Citroen.

Cheers, Ken
 
Are you changing the control arms or the rear bushes? The normal ride height is where you would set up any rubber bushes, but in the X7 the bushes are not clamped and the bracket that contains the bush simply bolts up to the subframe. If you buy new arms with new bushes than that is already pre-determined by the arm manufacturer. If you are replacing the bushes on the original arms (I would say preferable) then you have to fit them at the same angle as the original fitting. The factory doesn't sell the bushes separately, so they won't be giving any guidance on the fitting angle. The bracket that holds the rear bush is different for aluminium and steel subframes and some aftermarket items are better than others. If you are a hard driver, you could consider the Powerflex urethane rear bush option, which will last longer than others, but will also alter the ride as it is less compliant than the original part.
 
Hi
I am replacing the front control arms and was just not sure when I use the the hoist to lift up the car should I raise suspension to max height the same as when I get my tyres changed?
 
Well if this is the answer you were looking for, the suspension should be put in the normal height before the suspension bolts clamping the bushes tight are finally tightened. So the rubber is not prestressed in a unusual position. That would be the normal way for any vehicle suspension to be finally tightened sittting level at normal height not hanging down on jacks.
Jaahn
 
Ok I wasn't sure if I had to have the hydro pneumatic suspension raised first when removing the control arm first the when tightening put in the normal position.
As this is what I do when changing tyres them lower to normal position for alignment etc
 
You can let the wheels hang loose without the suspension forcing the arms to max height when changing tyres and doing this job. If you have the suspension pushing the arms to their maximum deflection, you will have the rubber elements very twisted, making it a more difficult job.

Note: that you've asked this question in three places, including two new threads. I've merged them together in the Citroen forum.

A thread you've found re replacing control arms, but I will link to it here:
https://www.aussiefrogs.com/forum/index.php?threads/c5-x7-front-lower-control-arm-bushes.148281/
 
Thanks very much for that
I was just concerned as once before the suspension dropped when I had my tyres changed and had to get the system repressurised.
 
I have another question if you can give some advice as well.

What is the best way to check the LDS reservoir level.

I have heard too many ways not sure which is the correct way.

I have had my C5 for six months now love it but need to know more about them.

Had a C4 before that loved it too but decided to upgrade to the C5 for comfort in my twilight years.

Haha
 
https://frenchcarforum.co.uk/forum/viewtopic.php?t=57819 From the UK Citroen forum.

This is the correct method - the same for the 2004 model:
The fluid levels should be checked with suspension depressurised (ideally), but with engine running, you can put it on the lowest suspension level and wait for it to fully lower and on level ground. The following diagram shows the levels for a C5 X7 - the BLUE being the maximum fill level and he ORANGE the minimum level.
LDS Fluid Level.png
 
That is the correct method, but you can only fully depressurise the suspension using the diagnostic tool or manually releasing the fluid pressure via bleeders at each end. For C5 and C6, the easiest way is to select the lowest** suspension setting and ensure the reservoir is approximately at the seam. The cap was originally not vented, but you can fit a vented cap. If it's going on to a hoist, release the cap a little so the tank can't bloat and fracture when there is a large change in height.

** Not the case for XM and earlier models with LHM or LHS as these are checked at the maximum height.

Be sure to compare the replacement control arms with what is fitted to the car before dismantling.
 
Frosty1966 said:
Thanks very much for that
I was just concerned as once before the suspension dropped when I had my tyres changed and had to get the system repressurised.
Click to expand...
I am intrigued by the statement. I know what you mean about tyre dealers who do not understand the functioning of the self levelling system ( lifting the car off its wheels can baffle it BUT it CAN readjust its height by itself IF given instructions and enough TIME to let the pump repressurise the system so it can go about its normal self levelling activity ).
The risk is the "tyre technician" will not know the car is not at operating height, ( it got there OK ) or give it enough time to re establish driving height before proceeding to drive the vehicle, which risks under floor damage as the car drags its belly across their lifting equipment. Been there ... Done that.
I do not let tyre dealers remove/replace wheels .. I take them a wheel or two and refit them myself.
 
Hi David so just to confirm as I am doing this tomorrow

It is going on a hoist so I leave the suspension in normal driving position and release the cap slightly.

Will releasing the cap slightly depressurise the system?
 
When the car is made to go to extreme low all the fluid that is usually in the cylinders to "hold up" the car is allowed to return to the reservoir ... releasing the reservoir cap allows the air inside the tank to escape without building up any internal pressure in the plastic tank. There is expected to be minimal pressure inside the plastic tank to prevent ingress of atmospheric dust or contaminants. In extreme cases these plastic tanks have been known to split, hence the advice about opening the lid. The cap has nothing to do with pressurising the hydropneumatic system. It is just there as a filler hole and to keep dirt out.
Placing the car on a hoist with the wheels hanging will trick the height correctors into thinking the car is too high, and it will
( as it should ) allow suspension fluid to be released.
When it time to restart the car and put it back on its wheels the pump may need a good couple of minutes to recognise that it is now too low and take some time to repump all the fluid that has been removed to return the car's ride height to its normal position. There are 8 spheres IIRC to re-energise. Some ( most ) of these spheres act as springs, some as ride stiffness regulators that are always there but not actually always being used.
Each sphere can have 300+ millilitres of high pressure nitrogen gas trapped inside, so the electric pump has to repump and re energise all of that released fluid volume as well as create the pressure to elevate the vehicle.
Allow time on restarting for the system to do its thing. You should be familiar with the grumbling noise of an active pump by now.
 
Total had to withdraw LDS from the market. It isn't clear exactly why but it is said to be an intellectual property issue.

PSA dealers now have "Liquide DA" produced by another company to the LDS spec. (DA stands for "direction assistée". LDS is used in power steering systems (eg sprung C5, C4, P308). I am using this.

The Penrite LDAS product is green which might be a source of confusion. It is used by some AF members.
 
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