Leaky hydraulic pump C5 x7 2.2hdi 2014

[gustav]

Hi!
Have a really leaky hydraulic pump. Solutions?

[mickthemaverick]

Am I right in thinking I can see a pin hole in the flange nut there?

[gustav]

No pin hole what I can see. Zooming in it seems to be coming from the green stuff. Bad sealing? Fixable?

[gustav]

This seems to be the culprit. Is this nut/part availeble as a spare part?

[wurlycorner]

Can't say I've seen of one leak from there before (though I'm by no means the oracle on these!).

If you can, I'd recommend sending it off to be overhauled and repaired for absolute peace of mind that there is nothing else wrong - though unfortunately I can't recommend anywhere now. The place I used before (BBA-Reman, that I had excellent service from, for a good price) is unfortunately no longer trading (for the second time...).

If you want to investigate further yourself, there is a good video showing the strip-down of one here

[mickthemaverick]

Thanks for posting that video Iain, a very informative watch. It looks like the diaphragm removed at around 7.10 may be the part that has failed or even the green ring seals further on. Either way I'd agree with Iain and send it off for professional refurb or replace the pump, there maybe recon options around where you send back your old pump after swapping over for a deposit refund arrangement.

[gustav]

Today i managed to get hold of a pump from a C5 2006. Is the bottom part the same as newer pumps such as mine? The part that is leaking on my pump seems to be same at least.

[wurlycorner]

I've never stripped one or overhauled etc - so if someone comes along who has or knows this definitively, then take their advice over mine.
In the absence of that at the moment though: The only parts I would be confident are the same across different part-numbered BHI units, is the motor.
The rest of the block could be different internally in terms of valve and chamber size etc. in order to achieve different damping characteristics?

However, if you strip the mechanical pump end on both and the parts you need look/measure identically, then I'd conclude they are the same.

[gustav]

This seems to be the culprit. Is this nut/part availeble as a spare part?

This was indeed the culprit. This is a pressure monitoring device meant to protect the pump house from overpressure. My guess is that the the previous owner didn't tell me he hit something big with the left wheel. The the left sphere was ruptured and the wheel alignment was way off.

The pressure switch/monitoring device has now been replaced but I am missing information about torque?