C5 MK1 strange one time hydraulic leak

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ml11ML
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C5 MK1 strange one time hydraulic leak

Post by ml11ML »

Hi guys,

I came back today after about 1 hour to my parked c5 nearly completely on the ground on the REAR end (front was fine) with puddles under both FRONT wheels.

I then put my weight on the tow hitch to see if it was entirely bottomed out. It wasn't but it did bottom out under my weight and stayed there instead of bouncing back.

I then unlocked it and it pumped itself straight back up and has been fine like that for an hour now with no dropping anymore. If I step on the tow hitch now it sinks and then bounces back up like normal after I step down.

The fluid from the rear seems to have somehow gone up the return line and then out the ruptured (on both front sides) front return lines which is why the puddles on the front. (Both front lines are actually too short to reach on full height?? Strange..)

I did just bring it back from a car wash (I did pressure wash the wheels area - some connection there?) so could some stray water have caused the leak?

I imagine one rear hydraulic cylinder somehow leaked while parked for this to happen or is there some other way for such an event to happen?

Best regards
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GiveMeABreak
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Re: C5 MK1 strange one time hydraulic leak

Post by GiveMeABreak »

It's possible you have been a bit over-zealous with the pressure washer!

Here are the return pipes for the the rear suspension (1) & (2)
C5 Return Piping.PNG
ml11ML
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Re: C5 MK1 strange one time hydraulic leak

Post by ml11ML »

Okay, it seems to be slowly dropping again (or has it ever even stopped? Not sure...) so the next course of action I think is to repair the front return pipes so that the fluid will actually return to the tank and then just drive it until it gets better or worse... It takes about 2 hours to fully drop at this rate so it's not that bad. I can't see anything obviously wrong at the back.

I made a little video of the drip/leak rate filmed at the broken front left return pipe.

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GiveMeABreak
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Re: C5 MK1 strange one time hydraulic leak

Post by GiveMeABreak »

Ok, that’s different then, these are front leak return pipes from the front struts.

I would secure these back on as you may have blasted them off with the pressure washer.

Then check your LDS fluid (on lowest suspension setting) is between the min and max level as you have list some fluid. Don’t overfill the system.
ml11ML
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Re: C5 MK1 strange one time hydraulic leak

Post by ml11ML »

Okay, so I managed to seal the leaking (upper) ends of the damaged front return pipes so now the fluid seems to be returning back to the lds tank instead of making a huge mess under the front tires.

Sadly the strut ends of the return pipes are much too short to be reattached as they would just pop off when the suspension extends and are also very easy to split. Can you give me some part numbers for the correct flexible return pipes from the strut end on the front?

I have also attached 2 pictures, one when parked and one after 2 hours that shows the rear end dropping slowly.
Attachments
20210911_145937.jpg
20210911_130817_1.jpg
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GiveMeABreak
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Re: C5 MK1 strange one time hydraulic leak

Post by GiveMeABreak »

Ok, so the leak-back hose is item (6) and needs the adjusting collar. These are still available.
Leakback.PNG
Item (6) is part 95050399 £21.34
The Adjustment Collar is part: 96127591 £5.44

These include UK VAT @ 20%, so whatever the equivalent is in your Country.

Below are the front return pipes. If it's any of these, the only one currently still available is item (4), the hydraulic Oil Back Harness for the RIGHT side. The Left side is no longer available from Citroen.

Item (4) below is part: 5270QL and is £36.83
front return piping.PNG
ml11ML
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Re: C5 MK1 strange one time hydraulic leak

Post by ml11ML »

Thank you Marc, good to know that the part 6 is still being sold.