I am an Activaist-v6 and a 2.1Estateerr

[Mandrake]

I would Jim....but those are plastic, thus non-porous so why bother ?

All Xantias have the fabric ones, not just the V6...

Thanks Jim, I thought that was the case but wasn't sure enough to put my neck out.

[Stickyfinger]

Oh....looks plastic on the drawings in Cit Service

[Stickyfinger]

This is fabric (No4) ?

[CitroJim]

Four is plastic but 5 in all models is fabric...

[Stickyfinger]

How would an Up-Pipe catch/drain water ?

[Stickyfinger]

Interesting "solution" on Activa FB pages

[Mandrake]

Solution to what ??

[xantia_v6]

Solution to what ??

What to do with that spare power steering reservoir?

[Stickyfinger]

To help reduce the water pressure on/in the header tank......reported as a way to stop it splitting every 6-12 months

[xantia_v6]

It can't reduce the pressure. The pressure in the (sealed) system is the lesser of:
* the vapour pressure of the coolant at the hottest point in the system and
* the release pressure of the cap.

You could plumb the Albert Hall (sealed) into the system and the pressure would be exactly the same.

Note that the ES9 XM has an identical cooling arrangement, but a better design of seam on the header tank and they never leak.

[Stickyfinger]

That was exactly my thinking.......unless the long pipe helps by expanding/swelling when the car is turned off. I really cannot see how this helps in anyway.
The cap is set to 1.4Bar (20.5psi)

I note the XM tank is also larger.

[Mandrake]

Even if it could reduce the pressure that would lower the boiling point of the coolant and make boiling the engine more likely - thus defeating one of the points of a fully pressurised coolant system. (Increased boiling resistance)

[Stickyfinger]

My thinking on it has not changed, that the problem is a material/design/joining method.
By hot welding a carbon filled injection moulded unit in this way a stress point is set up which cracks over time, simple as that.

[RichardW]

It's possible that mod reduces the running pressure of the coolant system. The pressure is mostly built up due to expansion of the coolant as it heats up, which in turn compresses the gas pocket in the header tank. By increasing the volume of the 'header' tank the pressure rise is less as the water expands. Boiling Point of 50/50 mix is around 108C rising to 129C at 1 barg, so if you drop the pressure to 0.5 barg(*) the BP would drop to around 118/119C - probably OK unless you are really thrashing it hard in really hot weather!!

* you'd need some volumes to do the calcs to see what the pressure change might be.

[Stickyfinger]

I do not like the very very long pipe either