C5 II suspension stuck on high after pump change

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

dulenator
Donor 2024
Posts: 66
Joined: 08 Dec 2021, 22:44
x 8

C5 II suspension stuck on high after pump change

Post by dulenator »

Hi all!

Another day, another issue. :roll:

The old pump started making strange noises, so I changed it with a good used one - first mistake.
I didn't notice it was from the older model, and it had a different ECU, so there was no communication with the solenoids.
I changed the ECU with the one from the old pump and everything came back to life, but not for long. :-D

The issue I'm having now is that the suspension won't go down.
It seems that the good used one is not that good after all and that the lowering solenoid thingies are stuck.

Now I would like to know how to depressurise the system without having the car put on the lift since I don't have one nearby
I don't have any other (safe) way to lift the car and let the pressure from the blocks, so I wonder if is it somehow possible to release pressure on the pump/solenoid block itself?

I need to change the pump for another one, that should be 100% working (refurbished and correct model), but now I can't since the car is on stilts and under pressure. :mrgreen:

P.S.
Lexia doesn't throw any errors and it tries to lower the car through the lowering test, but nothing happens except clicks for the start and end of an operation in the pump ECU.
User avatar
GiveMeABreak
Forum Admin Team
Posts: 37400
Joined: 15 Sep 2015, 19:38
x 5741

Re: C5 II suspension stuck on high after pump change

Post by GiveMeABreak »

Instructions in my post here (link below) - just make sure the vehicle is supported at the appropriate hacking points as this will bottom-out the car making it impossible to get a jack under!

viewtopic.php?p=649287#p649287
Please Don't PM Me For Technical Help

Marc
dulenator
Donor 2024
Posts: 66
Joined: 08 Dec 2021, 22:44
x 8

Re: C5 II suspension stuck on high after pump change

Post by dulenator »

The main issue is the rear end since I can't get it up in the air and another one is the one I just remembered - the pressure release screw is broken and cannot be extracted without breaking the block.
I bought the car like that and thought that the day I needed to use that would never come. :mrgreen:

I'll try to release the pressure through the pipes on the block or something like that since I don't have many other options. Just need to find a way to support the car... 8-[
The front end seems a lot easier and more accessible.
MGmike
Posts: 143
Joined: 29 Aug 2020, 18:29
x 39

Re: C5 II suspension stuck on high after pump change

Post by MGmike »

dulenator wrote: 02 Mar 2024, 19:15
Now I would like to know how to depressurise the system without having the car put on the lift since I don't have one nearby
I don't have any other (safe) way to lift the car and let the pressure from the blocks, so I wonder if is it somehow possible to release pressure on the pump/solenoid block itself?
The only way to let the pressure off at the pump will be very messy! But if you're prepared to have oil spray everywhere and a mega clean up operation.... carefully and slowly unscrew the two pipes that come out of the side of the pump.
dulenator
Donor 2024
Posts: 66
Joined: 08 Dec 2021, 22:44
x 8

Re: C5 II suspension stuck on high after pump change

Post by dulenator »

I'm not ready for the mess, but that's the only way to go. ](*,)
dulenator
Donor 2024
Posts: 66
Joined: 08 Dec 2021, 22:44
x 8

Re: C5 II suspension stuck on high after pump change

Post by dulenator »

C5 is dancing again! \:D/

I've managed to release the pressure on the pump side. Since the wheels were off the ground, fluid losses were minimal. :rock:
There was some pressure, but nothing special that a rag couldn't stop. I added less than 1L of fluid.

I decided to clean the old pump, since it looked better than the one I previously got, and return it where it belongs.
The car is on its legs and going up and down without any issues, and the pump is nice and quiet.

Thanks for the help, and let's see what comes next. :mrgreen: