Citroen XM Forum

Hi there,
I m new to the forum, and newer before own any Citroen...
I found very clean unmolested example of 98` XM V6 3.0 originated from Switzerland and decided to ship it home.
When arrived after more one month here I discovered leak came from Lhm pump plug look like 18mm in size just above alternator.
Have questions regarding how ( assuming there is high pressure in system ) to set up the car and de pressurize it to be able to get to the problem.
Can anybody help ? Thx.

With the engine running set the car to low then undo the 12mm bleed bolt on the regulator until pressure is released (about 1/2-1 turn). Do not unscrew fully as the internal ball can be lost.
Switch off the engine.
The system is now depressurised and safe to work on.

Union O rings are
4026 87 DIAM 16-TO 1,9 (2 off)
4026 88 DIAM 19-TO 2,4

If not using Citroen parts use 90 shore O rings for longevity.

My advice is to buy Viton o-rings with a cross section 0.1mm larger than the original.so that becomes 16x2 and 19x2.5.

I think that it is the larger seal that is 2 off and the smaller 6 off.
I usually buy them on eBay.

Thanks guys, one more think is the car need to be leveled when is depressurised or can I lift up front using floor jack?
Need to take A/C ( do not have gas) and Alternator off the car. Alternator got some LHM so need to be clean up.
Second problem is A/C where is the high side inlet? Found lower side, but can`t spot the other.
Thanks!

Due to the anti-sink valve closing, You won't be able to fully depressurise the relevant suspension circuit with the wheels hanging, but you're not working on that circuit, you are working on the primary circuit which will depressurise by loosening the 12mm bleed bolt.

Kris1998Xm wrote: ↑

Sun Aug 31, 2025 8:34 pm

Second problem is A/C where is the high side inlet? Found lower side, but can`t spot the other.
Thanks!

On the drier next to the battery?