Ride Height Measurement

[mlkey]

Hi,

 

Does anybody know the correct method to measure the vehicle height and wheel radius to enable to calculation of the value to be entered into the Lexia tool? The front of my C5 is riding high, and is also a little firm. I have checked the height sensor linkage, all is fine and clean under there. It seems like the front is simply riding too high. It still adjusts both the front and the rear when people enter / exit the car, so I believe this is all it is.

 

Thanks.

[mlkey]

Panic over.

 

I managed to obtain the correct procedure, and upon checking the front height, it was over 30mm higher than it should be. You can adjust the suspension both mechanically, and using the Lexia. I chose mechanically, as it is only possible to adjust by 10mm using Lexia.

 

If anyone needs the procedure for front and rear adjustments on a MK1, let me know.

[bobtuck]

I'd like to know this Mikey....could you possibly post here?

 

Many thanks.

 

Bob

[Bobster]

Panic over.

 

I managed to obtain the correct procedure, and upon checking the front height, it was over 30mm higher than it should be. You can adjust the suspension both mechanically, and using the Lexia. I chose mechanically, as it is only possible to adjust by 10mm using Lexia.

 

If anyone needs the procedure for front and rear adjustments on a MK1, let me know.

 

Hi Mikey,

 

I think my ride height may be too high but Haynes just says go to your dealer! Do you have the correct heights and how they are measured and how to adjust them?

 

Many thanks,

 

Bob H

[mlkey]

I am not able to post the document here, PM me your email addresses and I will happily send it over. :)

[TheGoose]

Panic over.

 

I managed to obtain the correct procedure, and upon checking the front height, it was over 30mm higher than it should be. You can adjust the suspension both mechanically, and using the Lexia. I chose mechanically, as it is only possible to adjust by 10mm using Lexia.

 

If anyone needs the procedure for front and rear adjustments on a MK1, let me know.

 

Hi Mikey, my name is Mike! I wouldn't mind having a pop at the mechanical adjustment on my C5 aswell, as I believe mine is running to high at the front too. It seems to be exactly how you have described it. Around 30mm to high. Its even noticeable from a great distance, when looking side on. I'm trying to find a cheap Lexia cable off Ebay. But there all the PP2000 type, and there expensive too. Do you know where I could buy a cheap one? Aftermarket or otherwise. And if you could send me over the relevant documentation on how to adjust the ride height sensor mechanically that would be a great help.

 

When my engine is running and the car has self-adjusted to normal height, (front higher) It appears that both my front wheels are cambering inwards slightly, I have just had 4 new tyres fitted as the prev. front tyres had exessive outside edge wear. I'm concerned that my new tyres will wear out quicker because of the camber? Could this be because the front is too high? Or is there something else going on?

 

The rears or rear wheel/s are cambering out slightly, but I'm aware that this could be my radius arm bearings (another job on my list).

 

My car is C5 mk1 Exclusive SX 2001 year. I will PM you my Email Address.

 

 

Cheers and Beers

 

Mike

[coastline taxis]

Just a word of caution.

Before you all go lowering the front end and taking the back end up remember that once your c5 hits 70mph on the motorway the BHI unit has a control law stored in its memory and WILL lower the front end by 15mm and the back end by 11mm without any warning to you. this could be the diference between the front wheels clearing the wheel arch at 70 mph or not clearing it. or you get a bit of a bouncy road and your bumper scraping along it at 70

[mlkey]

Just a word of caution.

Before you all go lowering the front end and taking the back end up remember that once your c5 hits 70mph on the motorway the BHI unit has a control law stored in its memory and WILL lower the front end by 15mm and the back end by 11mm without any warning to you. this could be the diference between the front wheels clearing the wheel arch at 70 mph or not clearing it. or you get a bit of a bouncy road and your bumper scraping along it at 70

 

The procedure is the official Citroen one, and is intended to be done when the vehicle is stationary, if followed to the letter there will not be an issue. Also, in my case I could set the car to full height and the pump would continue to run when suspension travel ran out as the height sensor was not correctly adjusted. After adjustment everything worked perfectly.

[mlkey]

Hi Mikey, my name is Mike! I wouldn't mind having a pop at the mechanical adjustment on my C5 aswell, as I believe mine is running to high at the front too. It seems to be exactly how you have described it. Around 30mm to high. Its even noticeable from a great distance, when looking side on. I'm trying to find a cheap Lexia cable off Ebay. But there all the PP2000 type, and there expensive too. Do you know where I could buy a cheap one? Aftermarket or otherwise. And if you could send me over the relevant documentation on how to adjust the ride height sensor mechanically that would be a great help.

 

When my engine is running and the car has self-adjusted to normal height, (front higher) It appears that both my front wheels are cambering inwards slightly, I have just had 4 new tyres fitted as the prev. front tyres had exessive outside edge wear. I'm concerned that my new tyres will wear out quicker because of the camber? Could this be because the front is too high? Or is there something else going on?

 

The rears or rear wheel/s are cambering out slightly, but I'm aware that this could be my radius arm bearings (another job on my list).

 

My car is C5 mk1 Exclusive SX 2001 year. I will PM you my Email Address.

 

 

Cheers and Beers

 

Mike

 

If the suspension is out of adjustment, I would adjust it mechanically rather than with the Lexia. I have sent the details as requested. If you put the car on full height, does the suspension pump cut out withing 15 to 30 seconds? If so the chances are your suspension is not too far off the correct height. My pump would not stop running when the full height was requested and before I adjusted everything.

[TheGoose]

My suspension cuts out pretty much instantly once maximum height is reached. The idea of lowering the front is more of personal taste really, I think the front rides too high, it may be ok like this, but like i say I have this Inwards camber issue aswell. Any ideas what could be causing this? Thanks for the .PDF file you sent, I may consider lowering the front end by a small amount only (lets say 10-20mm). As by what Coastline has said once you hit 70mph the car lowers again by 15mm, so whatever adjustment I end up making to the front, i will have to compensate for an extra 15mm of lowering for speeds over 70mph.

 

If I where to do this, could this then cause the pump not to cut out when it should on max height? As I would of thought that as long as the Potentiometer moves to the maximum height position, then the ECU would think the cars at max height, surely this would then cut out the pump. With your issue, maybe someone has over adjusted the Potentiometer too much, or its faulty? Whereby mechanically the suspension has reached the top but the Potentiometer has not? Then the ECU would be constantly activating the pump, waiting for the Potentiometer to reach the max position?

 

Just a thought!

 

Thanks

 

Mike

[mlkey]

My suspension cuts out pretty much instantly once maximum height is reached. The idea of lowering the front is more of personal taste really, I think the front rides too high, it may be ok like this, but like i say I have this Inwards camber issue aswell. Any ideas what could be causing this? Thanks for the .PDF file you sent, I may consider lowering the front end by a small amount only (lets say 10-20mm). As by what Coastline has said once you hit 70mph the car lowers again by 15mm, so whatever adjustment I end up making to the front, i will have to compensate for an extra 15mm of lowering for speeds over 70mph.

 

If I where to do this, could this then cause the pump not to cut out when it should on max height? As I would of thought that as long as the Potentiometer moves to the maximum height position, then the ECU would think the cars at max height, surely this would then cut out the pump. With your issue, maybe someone has over adjusted the Potentiometer too much, or its faulty? Whereby mechanically the suspension has reached the top but the Potentiometer has not? Then the ECU would be constantly activating the pump, waiting for the Potentiometer to reach the max position?

 

Just a thought!

 

Thanks

 

Mike

 

I think you are asking for trouble personally. I set mine to the correct height and it looks low enough at the front when stationary. It only just clears speed ramps now. Good luck with it.

[shader]

 

If the suspension is out of adjustment, I would adjust it mechanically rather than with the Lexia. I have sent the details as requested. If you put the car on full height, does the suspension pump cut out withing 15 to 30 seconds? If so the chances are your suspension is not too far off the correct height. My pump would not stop running when the full height was requested and before I adjusted everything.

Hello mikey,

 

I'm new owner of a C5 from 2004. Please send me the procedure for checking and lowering the front end of a C5. I suspect that my front end is too high for my taste. Thanks in advance.

[citrophile]

Hi mlkey

 

Am having an issue with the front ride height on my C5, could you send me the procedure for adjusting it.

 

Thanks

 

Rob

[citrophile]

Help!

 

Can someone with a 2005 C5 tell what height their front suspension is at when parked on level ground locked with engine off, measured from ground to wheel arch.

 

Mine at the moment measures 75cm which to me looks about 5cm too high.

 

Thanks

 

Rob

[Johndouglas]

Mine at the moment measures 75cm

 

Mine is at 72.5

[citrophile]

thanks john

am going to adjust the sensor linkage on the roll bar to see if I can get it down to that

rob

[Johndouglas]

am going to adjust the sensor linkage on the roll bar to see if I can get it down to that

When comparing one ride height with another, bear in mind other influences.   Tyre pressures and wheel size.   Both will alter the ground to wheel arch measurement.

 

Incidentally, my wheels are 215.55x16 inflated to 2.5bar

[paul.h]

This is from the Citroen manuals for checking the front height -

 

2. Preliminary operations

Check the LDS fluid level (see the relevant operation).

Verify the tyre pressure.

Place the vehicle on a 4 -post lift.

Put the vehicle in the normal position.

Release the parking brake.

Start the engine.

3. Checking each axle in turn

Push up the vehicle.

Let go when the weight becomes too important.

The vehicle will drop, then rise and settle.

Measure the height.

Push the vehicle down.

Retain the vehicle in this position ; let go when it rises.

The vehicle will rise, then drop and settle.

Measure the height.

Take the average of the 2 measurements.

 

 

 

Dimension " L1" for checking the front height is measured between the flat section "b" on the underside of the front subframe and the centre line "a" of the road wheel.

This method does away with all the variations of measurement arising from the following factors :

• Types of wheels fitted
• Vehicle load
• Wear or incorrect inflation of the tyres

H1 = R1 - L1.

H1 = Front height (± 6 mm).

R1 = Wheel radius ( mm). From the wheel centre to the ground.

L1 = Theoretical dimension between the flat section of the front subframe and the centre line of the road wheel.

L1 = 140 mm. (the underside of the subframe should be 140 mm below the wheel centre)

The measurement of the front dimension " H1" is between the ground and the measuring zone on the underside of the front subframe (at the rear of the front suspension arm fixing yokes).

 

If the height is more than 10mm out, the height adjuster is moved, if less a Lexia is used .

 

-----------------------------------------------------------

Additional info for checking the rear height 25/7/2014.

 

The rear height H2M is measured between the ground and the zone "a" on the crossmember (behind the rear sphere).

4.5. Calculating the rear height H2C

H2C = R2 + 73 mm .

R2 = Rear wheel radius ( mm).

Compare :

• The value measured H2M
• The value calculated H2C

Adjust the rear height if necessary.

[Craigy]

Many Thanks

[joiner200_0]

my c5 estate is riding high at back anyone know how to lower it down I can lower it from boot and front of car but when I start her up the back just goes back up again and its a really hard ride

many thanks

[paul.h]

Welcome to the forum.

 

How much higher is the back when compared to the measurements obtained following post 18 ? If up to 10 mm out then it should be adjusted using a Lexia. If more than 10 mm out then the adjuster should initially be altered by moving on the rear anti roll bar to get to within 10 mm before using the Lexia - first make a reference mark on them before any alterations. Before doing anything the car should be on a ramp or axle stands and with the battery disconnected since touching the height sensor can cause the car to drop to a very low level, only a few inches above the ground and if under the car you would be squashed - without such facilities it may be better to use a dealer. It is also possible the hard ride could be a fault with the spheres. Haynes also mentions firmness regulators on cars with hydractive 3+ suspension.

[Friis]

Hi,

 

Would be happy if someone could PM me a copy of the document. Have tried to contact mlkey without success.

 

Friis

[paul.h]

Welcome to the forum.

 

Post 18 is the Citroen procedure for checking the suspension height with a few extra words to help explain it. mlkey has not been on the forum since July 2012 so probably no longer has an interest in Citroen cars.

[j0hn52]

The hydropneumatic system on the C5 is way too complicated and offers no benefits over the sprung version. In fact I prefer the sprung version. 

[paul.h]

Welcome to the forum.

 

Many of us have the C5 for towing a caravan and want the self leveling suspension provided by the hydractive suspension.