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For all our Dutch forum-members, this is a translation of this thread .
Every owner of a CitroŽn xm will have a complaint on their suspension now and then. But what are the causes, and what to do about it?
Actually, there are a few problems that cause’s 90% of all complaints. Here’s what they are, and how to solve them.
When your suspension isn’t soft enough, it’s as stiff as a bmw or you just want to know it’s 100% in good nick, start with checking the overall state of the hydraulic system. It contains shortly 3 elements;
1. the spheres
2. the suspension oil (the green stuff)
3. the suspension computer
Every xm has it, suspension spheres. There’s a difference in number however. The early ones until 1994 usually have 5 spheres, one on each wheel, and a main (reserve) sphere. Later models (type 2, 1994 until 1997/1998) have an extra sphere on each axle, so 7 in total. These extra spheres take care of automatic sport suspension in several situations. Even later models of 1996 up to 2000 have an anti-sink sphere or smack sphere, which should keep the xm awake and up on her feet.
How they work is a different story, and you can find it on the internet or maybe here some day. What’s important to remember, is the pressure on the spheres. You can have them checked at your local CitroŽn expert, or, not likely however, your dealer. And off course you can change them yourself. To do this, undo the pressure bolt on your oil distributor and take off the sphere with an oil filter wrench or a blunt axe. Off course this is the short version, a detailed description will be following shortly.
LHM (hydraulic) oil
If youíve checked your spheres, then youíve seen the LHM. Your xm brakes and suspends on hydraulic oil. Itís green (it should be!), and it is supposed to be enough in the reservoir. If youíve bought your car recently, and there isnít a history, check it! On top of the big black reservoir, thereís a transparent tube with an orange floater in it. The orange dish should be in between the two red lines on the tube. And check the color of your oil by dipping a white cloth in it. It really should be toxic green, not brownish. When itís not green, change it! And hereís how to:
Put your xm in lowest position, turn your pressure bolt (13mm) 180degrees open to depressurize the system, then remove the hoses on top of the reservoir, and take out the complete reservoir. Clean it with petrol (donít forget to put out your cigarette), clean the filters! Then putting everything back into the car, fill it with clean LHM oil or use hydroincage (thatís red oil which cleans your system. Drive with it for 5thousand kmís, and then change it for normal LHM). Fasten the pressure bolt, start your car, put it in highest position, take of the rear wheels and flush your brakes using a transparent hose on the brake valve. Be careful not to break off the valve. Do the same with your front brakes, and fill up the reservoir.
And again; this is the short version; a detailed description will be following shortly.
But wait, thereís more!
Still not satisfied about your comfortable magic carpet ride? Than thereís the computer. Almost every xm has one. But, if you donít have a sport suspension switch next to the gearlever, you donít have a computer.
A great a number of sensors is telling your computer how it should behave. Thereís one in your steering wheel, one connected to the brakes, to the gas pedal, etcetc. And when one getís dirty or sensors a fault, your computer switches to emergency position, in which it just wantís to get you home.
How do you know your computer is in emergency position? At the top left on your dash, thereís the sport suspension indicator light (the orange one). It should burn for a few seconds after turning on ignition. When it doesnít, thereís a fault stored inside your computer. It often results in permanent stiffness, or not working at all. Especially on later models, you will know the difference in speedy corners! Your car doesnít work anymore. In fact, maybe 30% of all xm owners have ever experienced the real working xm hydro active suspension, simply because their computer is in emergency position!
If your light doesnít burn, itís time to read-out your computer, and reset it. How to? Just read this thread. There you can read how to read-out and reset your computer without visiting your garage or dealer (because they donít know how to) and make your xm fly again.
Still not satisfied?
Then there is a chance your diodes are burned. It sounds bad, but itís not. At your axles and sphereís, thereís these valves opening and closing. They are controlled by your computer, and protected by diodes, and they donít last a lifetime. Thereís just one way to check, and thatís opening your suspension computer (yes, thatís the scary bit) and check for any brown spots on the print plate. If you do, contact me for more details!
If you own an xm, but she doesnít suspend the way you want her to?
1. Check your sphereís for the right pressure, or change them!
2. Check your LHM. Is it toxic green? No? Change it!
3. Check your sport suspension light. It doesnít come on when turning on ignition? Read-out and reset!
If youíre having problems checking your system, open a new thread or hook on to existing ones. And of course, you can contact me for reading out and resetting your computer.