Very strange ABC suspension problem

[Dieselman]

I don't think it would matter as there's 185 bar pressure in the circuit. I didn't try it though but that what I would personally do.

Surely, if the wheels are hanging, the system won't call for fluid as the rams are at full extension.

185 Bar pressure isn't an issue as each stroke of the pump will only deliver about 5cc of fluid.

 

[Alex]

Surely, if the wheels are hanging, the system won't call for fluid as the rams are at full extension.

185 Bar pressure isn't an issue as each stroke of the pump will only deliver about 5cc of fluid.

I believe there should be enough pressure to bleed each corner. Like when a wheel or two hit a pothole or road undulation. I didn't try so wouldn't know for sure though.

m2287, did you try it with wheels hanging or are you celebrating New Year now?

 

[V12]

Try simulating load on the wheels with a trolley jack?

 

[m2287]

Had afew too many last night! I'm going to try one more time later, I don't like to give up! I'll let you all know the outcome.

 

[Dieselman]

I believe there should be enough pressure to bleed each corner.

If the wheels are hanging the upper sensor will activate and stop any fluid flow, otherwise it would attempt to burst the ram seal or pipe due to constantly adding more fluid when set to max height.

 

[Alex]

If the wheels are hanging the upper sensor will activate and stop any fluid flow, otherwise it would attempt to burst the ram seal or pipe due to constantly adding more fluid when set to max height.

That makes sense, however would there not be some kind of pressure in the strut?

 

[Dieselman]

That makes sense, however would there not be some kind of pressure in the strut?

How, it's hanging. If anything it would be negative pressure.

 

[Alex]

You're right Dieselman. Had to do some reading on Citroen and ABC hydraulic suspensions and apparently, there wouldn't be any fluid in the chamber at all when the strut is fully extended.

 

[m2287]

So to bleed the strut, the car needs to have the bleed screw open, and needs to be on the ground on the lowest setting when starting?

Then start the car, press the raise button and let it do it's business.
Then shut the car off and close the bleed screw.

Should I only open the bleed nipple slightly so that most of the fluid will be directed towards the strut?

 

[Dieselman]

Where is the bleed nipple located?

I would start the car, set to high, open the bleed valve, when fluid comes out, close the valve to get the car to lift.

EDIT:
I've just had a look at the pipe schematic and see the bleed valves are located in the supply pipes, low down. The layout isn't good for bleeding, but once you have fluid past the fluid control valve it will self bleed with enough raising and lowering.
A return pipe would have saved the need to bleed.

 

[m2287]

Ok this car is not happy for some reason.

The passenger side bled fine and works perfectly.

I then bled the drivers rear strut, fluid came out of the nipple so I switched off and tightened that up. Perfect I thought!!!!

Started the car back up and pressed the raise button, the passenger side went up but the drivers side stayed on the floor (front and rear). Tried this several times with the same outcome. Interestingly however I got NO ABC warning lights at all!

There must be a problem elsewhere, I'm going to have to take it to a specialist and get it on to STAR. I'm guessing it's a sensor or the ABC control unit. Thanks for your help so far uys!

 

[Dieselman]

Did you bleed the front as well. If the valve is still located on the left side on RHD cars, there is a lot of pipe to bleed for the right hand side.

 

[m2287]

I didn't bleed the front, would this be necessary as I thought it is controlled by a seperate valve block?

Also surely this would mean that the rear strut which was bled would have worked fine and just the front drivers strut would have been stuck on low.

Thanks again btw!!!

 

[Dieselman]

Unless you bleed all the pipes, you probably can't guarantee a reliable flow of fluid. Air in sealed hydraulic systems has a marked effect.

 

[Alex]

I'd bleed some more. Have someone pour fluid in the reservoir while you do the nipples.

 

[m2287]

I'll go again later on!

 

[m2287]

Ok so I've bled and bled and bled some more!!! Car was still doing the same, would only raise on the passenger side.

Got ****** off and thought **** it I'll take it for a drive round the block and see what happens! (Just went around my culdisack!)...

Anyway as soon as I got to 30mph, the drivers side raised up and the blue abc light came on!

Pulled over, pressed the raise button and it did nothing at all so restarted the car and the drivers side dropped right back down again (quickly but as if it was under pressure)... It then went back to only raising on the passenger side.

I am now convinced this is a problem with a sensor or ecu... What do the panel think!?

 

[m2287]

To confirm, every time I turn the car off the ABC stops working on the drivers side. When driving slowly from 0-10mph, the passenger side seems to raise itself up all the way, even when it's on the lowest ABC setting. Then once I hit 30mph, the drivers side raises up and the passenger side lowers so the car is level and the ABC blue warning light comes on. The car then stays like this until I turn it off. Even when it's turned off, the car stays at this level, it's not until you turn it back on that the drivers side lowers back down to the lowest setting.

I have also noticed that when on the lowest setting, the passenger side doesn't go as low as it should!

 

[mercedescl500]

Ok so I've bled and bled and bled some more!!! Car was still doing the same, would only raise on the passenger side.

Got ****** off and thought **** it I'll take it for a drive round the block and see what happens! (Just went around my culdisack!)...

Anyway as soon as I got to 30mph, the drivers side raised up and the blue abc light came on!

Pulled over, pressed the raise button and it did nothing at all so restarted the car and the drivers side dropped right back down again (quickly but as if it was under pressure)... It then went back to only raising on the passenger side.

I am now convinced this is a problem with a sensor or ecu... What do the panel think!?

Aidan

I think you might want to recheck the rear abc acceleration sensor you recently fitted. It is possible that you misaligned the abc strut connector cable. It's right next to the sensor and dislodges ever so slightly. This would cause both a ABC warning message and drop the suspension on the drivers side. Also recheck the sensors which you bought as they were not brand new they might be faulty. Do you have access to Star or a version of carsoft ?

 

[mercedescl500]

Aidan

I think you might want to recheck the rear abc acceleration sensor you recently fitted. It is possible that you misaligned the abc strut connector cable. It's right next to the sensor and dislodges ever so slightly. This would cause both a ABC warning message and drop the suspension on the drivers side. Also recheck the sensors which you bought as they were not brand new they might be faulty. Do you have access to Star or a version of carsoft ?

I just read your last post. Your ABC pump will produce more pressure whilst driving which would indicate the pump might be dying. Getting the car on Star would be your best bet as pentosin and replacing parts will be more costly.