C5 2007 LDS tank issue

[GiveMeABreak]

Maybe someone with more knowledge can help:

For my C5 2.0 HDI VIN VF7**************[VIN obfuscated, can be read by forum staff], I want to replace the LDS tank as it is slightly leaking. I ordered a new original one and realised when I got it, there is no connection on the top for a return line, where the old one has this connection and a small rubber hose is attached. ("Retour suintement" I guess). Interstingly, there is a blind "nipple" at this spot.

What function has this small hose? What was the change on later models (I guess)? As I didn't find the correct tank, I will be forced to adapt this one. Not easy, as the blind nipple is very short...

On the new tank is a writing "avec retour suintement" and "sans retour suintement" plus a bunch of numbers.

Thanks for your comments!

[toolfan]

Here a pic of the old tank with the return hose.

[GiveMeABreak]

Hi

No need to panic.

There was a modification made to vehicles from build 10248 (29th Nov 2004), concerning the integrated BHI.

Basically on your particular vehicle with Hydractive 3 Plus, the return of the LDS fluid is no longer via an external pipe, but via an internal duct within the BHI. This is done without any modification to the reservoir.

The new tank should be delivered with a pipe (4) and a clip as seen below:

A = Old BHI
B = New BHI with modification made using supplied pipe and clip.

[toolfan]

Thanks Marc!

There was no extra pipe included, but shouldn't be a problem to find a similiar one.

But I am not sure if I understand correctly: I don't see on the old BHI in the picture the top return pipe like I have on my car. Should I just connect the top pipe to the lower connection as in B?

Anyway, I will have to see in situ....

[GiveMeABreak]

All I can advise for action is:

Perform the following operations:

1. Uncouple the Pipe (3)
2. Replace the BHI
3. Uncouple the Pipe (4) between the stiffener regulator return and the LDS fluid reservoir
4. Fix the pipe (4) on the LDS fluid reservoir using the clip

[toolfan]

Ok, I will have to check what BHI I have.

[coolerl]

Hi

No need to panic.

There was a modification made to vehicles from build 10248 (29th Nov 2004), concerning the integrated BHI.

Basically on your particular vehicle with Hydractive 3 Plus, the return of the LDS fluid is no longer via an external pipe, but via an internal duct within the BHI. This is done without any modification to the reservoir.

The new tank should be delivered with a pipe (4) and a clip as seen below:



A = Old BHI
B = New BHI with modification made using supplied pipe and clip.

Hi Marc,
I have one question related to this.
When I got the car from my father, he didn't remember if there was any hose attached to the LDS reservoir ( VIN VF7**************[VIN obfuscated, can be read by forum staff] )
Now the reservoir looks like in the attached pictures, with no pipe from the reservoir to anything.
As the picture shows, there are obvious LDS fluid leaks from there.
Should I plug that outlet or there should actually be a pipe going from there to somewhere in the pump

I had to refill almost 0.5l of LDS to get the level back to the normal point.

Thanks,
R.

[GiveMeABreak]

That pipe at the rear of the reservoir is the connection for the return supply from the suspension spheres. Hopefully the following will help you determine what the connections are.

Reference	Function	Component
"A"	Return	Cylindres De Suspension
"B"	Suction Line	Integrated BHI (BHI)
“	“	Power Steering Pump
"C"	Return	Integrated BHI (BHI)
"D"	Return	Power Steering Pump

On the MK II C5, the excess LDS fluid from the struts is returned back to the reservoir. If you look at the diagram below, you can see at (6) the leak back hose from the strut:

Shown again here:

Here are the pipes for the return of the fluid:

Return Piping Front

Return piping Rear

Unfortunately none of these are available from citroen.

[coolerl]

Thank you Marc!

Problem is that I don't see any pipe that can be connected to the reservoir.
Also I don't see any leaks anywhere (besides the obvious one, on the reservoir, that is left in an open end).

I know that 2 years ago the left side rear pipe was replaced due to the fact that is was corroded and it failed but I don't think they could have replaced it with one that has no return.

So form what you checked, according to the VIN, there should be a return path on my model, right?

Thanks,
R.

[GiveMeABreak]

Yes, if you look at the 'Return Piping Front' diagram, you can see that the front right strut return pipe (4), and (3) the front left strut return pipe go into the union. The pipe (2) connects to the outlet at the rear top of the reservoir that you are missing.

The REAR return pipe (2) on the second diagram also connects to the same union (in the middle). The second return pipe from the rear (1) would appear to go elsewhere.

So the question is if you are missing the pipe from the union to the LDS tank, where is the leak-back fluid going from the 2 front and 1 rear struts?

[coolerl]

Indeed that is a very good question
That is why I wanted to confirm that this is the correct piping for my model.

I'll investigate on the car and see if something is missing or if there is actually a leak hanging somewhere.

Thanks a lot for your help.

Yes, if you look at the 'Return Piping Front' diagram, you can see that the front right strut return pipe (4), and (3) the front left strut return pipe go into the union. The pipe (2) connects to the outlet at the rear top of the reservoir that you are missing.

The REAR return pipe (2) on the second diagram also connects to the same union (in the middle). The second return pipe from the rear (1) would appear to go elsewhere.

So the question is if you are missing the pipe from the union to the LDS tank, where is the leak-back fluid going from the 2 front and 1 rear struts?