2009 citroen c5 x7 saloon suspension change

[Jameswhereisit]

Hello everyone. I own a 2009 Citroen c5 x7 saloon 2.2 hdi vtr+ nav. I am looking into changing my hydraulic suspension to standard shocks and springs. I have been told that the suspension from a Peugeot 407 saloon would bolt straight on, is this true? Can it be done? Has anyone else done this?

If it is possible… is anyone breaking a 407 saloon and can I buy your suspension?

[Kees]

Why from a Peugeot? You can also use the parts of an C5 X7 without hydraulic suspension, they are the same parts.
I also think you get problems with the rest of the hydraulic system!!
Because the hydraulic pomp will keep working, because it will correct the body height.

[Kees]

I also wonder, the reason why you want to change to metal springs and different dampers?
Greetings,
Kees.

[Jay-Bruce]

Mechanically the C5 (X7) and 407 are virtually identical, so yes, you can change your C5's hydraulics to 407, or c5 steel suspension. Although be cognisant of the fact you'll need to do some plumbing to set up a new power steering reservoir as the tank for the hydractive 3+ in your car is also your power steering fluid tank.

However, the bigger problem that prevents this being a simple bolt-on-job-done affair, is that unlike Citroens of yore, say the BX, the C5 (X7) has ECU(s)* (see footnote for more info) for the suspension, and are networked to other systems like the BSI etc. Those ECU(s) are going to get cranky and throw up all kinds of fault codes and or warnings on the dashboard if you do this as a straight mechanical swap.
*inline 4 C5's have one ECU and 2x height sensors for the hydraulic suspension, whereas v6 models, both petrol and diesel have two ECUs and 4x height sensors

You'll need some diagnostics equipment to depressurise the system safely before you start ripping it apart / ripping it out

I often use delphi for this rather than Diagbox, but you'll need some sort of decent computerised diagnostics tool, ideally the peugeot/citroen specific application on a laptop. The reason I express a preference for you doing this with a peugeot/citroen laptop rather than something like my beloved delphi diags is, and I don't know this off the top of my head, but using a lexia / peugeot planet / diagbox equipped laptop, it may be possible to go into your vehicle's BSI etc and reconfigure your car from hydraulic to steel suspension. That's your best bet at being able to overcome all the electrical gremlins associated with this swap. Alternatively, you could get a full lockset including fuseboxes and ecu etc from an almost identically configured c5 and change them at the same time. I don't know if you could use the electronics from the donor 407 that you get the suspension from as I don't know how their ECU and instrument binnacle connect to each other. It'd need to be a pretty close match, as I done a lock set swap on a 308 a few years ago, and the donor car had a different climate option, either it had AC and our car didn't or vice versa, and we ended up with something screwy like full on fan all the time, and unable to divert airflow from dashboard buttons because of the incompatability with the control modules.

Assuming what i've outlined for the ECUs is something you find doable, you'll also have a 40amp circuit that powers the pump to "delete", or somehow make safe when you yoink the BHI (ecu, pump, valve block combo thingumy behind right had headlight). Although you could probably get away with pulling the appropriate 40a maxi fuse on the back of the engine bay fusebox...

And at the risk of sounding like your nagging uncle, changing from hydraulic suspension to steel suspension is a significant modification to the car and you really ought to notify your insurance company about it, lest you run the risk of them invalidating your cover because of "undeclared modifications".

But, the biggest question I've got to ask is...

WHY?

Why are you contemplating converting your car to steel springs? Are you having problems with the hydraulics? What's wrong with it? We have a great pool of expertise on that system within the forum, and are more than willing to help.

[Kees]

I also asks the same question, but get no answer!!