C5 front suspension stuck at highest setting

[Gibbo2286]

On mine some will recall the front height corrector electrical plug was full of blue corrosion, cleaning it up and refitting it sorted the height problem, mine was stuck at the top.

Usual warnings, if you're getting under there and messing with height correctors be sure you have the car properly supported on axle stands or you could end up squashed flat.

[myglaren]

Hi Marc
Thank you for posting detail information.
I have to find hydrolik pump as its completely dead. Car is at lowest settings. When I raise suspension and lower it, i can see the change in the hydrolik level but there is no movement.

Once it is fixed then i will troubleshoot front height corrector.

The pump is usually OK but the motor gone bad.
May be recoverable.

[zeeshanzaki]

I am going to remove the pump and see if it can be repaired otherwise need to find at wreckers.
Now the pump is not working and system can't be depressurised, do I still need lexia for changing pump?

[GiveMeABreak]

You can depressurise each axle independently. There is a manual way if you don’t have Lexia. You’ll need to match the unit if replacing whole.

[zeeshanzaki]

Hi Marc
How do i depressurised each axle and from where. Is it not depressurised when you disconnect metal pipes from the pump.
Thanks

[GiveMeABreak]

Ok, so on your C5 which is Hydractive 3+:

To depressurise Manually:

The vehicle should be in the lowest suspension position - but if you can't do this because of the fault, then I don't know how this will affectt he operation - but I suspect there will be a lot of pressure - so caution is advised - wear some protective goggles, as I suspect there will be a lot of LDS coming out under some pressure. Do not re-use any LDS that comes out.

Front suspension: Undo the detensioning screw (3) by one turn. Wait for the pressure in the hydraulic circuit to fall fully.	Rear suspension: Undo the detensioning screw (4) by one turn. Wait for the pressure in the hydraulic circuit to fall fully.

[zeeshanzaki]

I will buy lexia if I decide to replace pump that way it will be properly done.

I forgot to mention that when I drivew car home, I applied some wd40 in front height corrector area without looking it’s proper location. Do you think this would have damaged height corrector and caused pump failure. Because pump was working even though i show smoke coming out of it.

[xantia_v6]

The pump was already damaged to some extent when you saw smoke. Either through overheating, or through internal contamination of the motor.

[GiveMeABreak]

That's why I suggested you get the car towed back - so as not to put additional stress on the pump motor - running it constantly for the journey back has likely burned out some of the internal components at this point. The motor only operates for a few seconds at a time under normal operating conditions to maintain required pressure.

Another member here had a faulty electrical issue with hi pump abroad - his electrical and it wouldn't operate, but he managed to bridge the fuse to get the pump working at the start of each journey, then disconnected the bridge when it was at normal height - the system maintained enough pressure for him to get back without the pump working - although it was not ideal.

But in your case you have probably run it for too long at this point.

[zeeshanzaki]

Hi Marc
Car is already at the lowest sitting on bump stop and lds tank full. Do you think there will be any pressure in the system. The reason I am asking is if I have to replace pump without lexia than I don’t need to release pressure from both axels.
What I am planning to do is raise the right side of the wheel and support with stand. Remove wheel arc and drain all the fluid from the tank. Then remove the tank. Disconnect high pressure pipes and remove the pump.

Thanks.

Ok, so on your C5 which is Hydractive 3+:

To depressurise Manually:

The vehicle should be in the lowest suspension position - but if you can't do this because of the fault, then I don't know how this will affectt he operation - but I suspect there will be a lot of pressure - so caution is advised - wear some protective goggles, as I suspect there will be a lot of LDS coming out under some pressure. Do not re-use any LDS that comes out.

Front suspension: Undo the detensioning screw (3) by one turn. Wait for the pressure in the hydraulic circuit to fall fully.	Rear suspension: Undo the detensioning screw (4) by one turn. Wait for the pressure in the hydraulic circuit to fall fully.

[zeeshanzaki]

I hope the pump is ok because it will be difficult to find same pump. So far wherever I inquired they have 4 cylinder or hid pumps.

Hi Marc
Thank you for posting detail information.
I have to find hydrolik pump as its completely dead. Car is at lowest settings. When I raise suspension and lower it, i can see the change in the hydrolik level but there is no movement.

Once it is fixed then i will troubleshoot front height corrector.

The pump is usually OK but the motor gone bad.
May be recoverable.

[GiveMeABreak]

All information I have suggests you must depressurise the circuits before replacing the pump. So you need to get thecar off the ground on axle stands and then depressurise the front and rear circuits.

[zeeshanzaki]

So all the wheel must be on stand when depressurising system with or without lexia

I found few pumps, so there any way to test whether it is working or not before installing.

[GiveMeABreak]

I say put the car on axle stands as otherwise you won't be able to get under the car to work on it if needed.

As for the pumps, make sure it is the same number as your existing pump - there should be a label with a long number on beginning 96 or 98 - match that one up. As for testing - you wont want to dry run the pump anyway - but there should be 2 x 2 pin connectors on the pump motor:

Pin 1 B7740 is the power from the Maxi Fuse in the engine fuse box. (May be grey coloured wire)
Pin 2 M7740 is the earth (Yellow / Green)

Second 2 pin connector (with only one wire)
7780: Electric Pump Unit Motor Command (to the suspension ECU) (May be a white wire).

[zeeshanzaki]

I decided to remove the pump today before ordering parts. Everything went smoothly but can't disconnect power connector from the motor. I pulled the red clip but the connector is not disengaging from the motor. Looks like someone already changed the pump in the past. Connector is also partially broken. Is there anyway to disengaging without completely braking it. If I can't remove the motor, i am going to put it back and sell the car to wrecker.