C5 X7 Steering pipe replacement

[bobins]

Quickie question - anyone know if the subframe has to be lowered to replace the low pressure power steering pipe on a C5 X7, or can it be removed and replaced with luck, skill, ingenuity and plenty of swearing in appropriate places without the need for dropping the subframe ? DocBackup doesn't cover the procedure - at least not the copy I've got !

[bobins]

To answer my own question - no it doesn't
I did the job this afternoon and it took a leisurely 2-odd hours. A bit fiddly and requiring a laid-back attitude to problem solving as you have to work out how to remove and then refit a fairly delicate rigid pipe that doesn't want to go where you want it in a confined space with lots of obstacles in the way
One for The Krypton Factor methinks

[white exec]

. . . as you have to work out how to remove and then refit a fairly delicate rigid pipe that doesn't want to go where you want it in a confined space with lots of obstacles in the way

Citroen have got this sort of thing down to a fine art

[bobins]

The replacement part had a few bends in different places in comparison to the original part, but all the attachment points matched up - I'd say that was a bit of Citroen evolution in order to make installing the replacement part a tiny bit mildly easier.... although the whole process seems comparable to the proverbial "sticking a piece of cooked spaghetti up a cat's backside at arms length when you can barely see what you're doing and the cat doesn't want you to carry out the procedure"

[Paul-R]

Does any cat?

[wheeler]

Out of curiosity what was the part no of the pipe & how long did you wait on it?
I’ve currently been waiting on one since The 14th of May & stil no sign of it.
Think it must be a PSA back order record

[bobins]

Sorry, I don't know the part number as it came with the rack when I bought it. I know there were around 5 (at least) different evolutions of the pipe as they modified it as the months went past.
I'm not wholly convinced the pipes fail due to corrosion, I think they partially rely on a 'crush fit' with the clamp holding them tight into the pipe socket. If the ridge that's pressed into the aluminium pipe gets worn or squashed in use the the pipe won't seal properly. The old pipe that I removed still had a clean mating face on it but leaked nonetheless.

[bobins]

To clarify my ramblings above - here's what a leaking low pressure pipe looks like. I'd tried numerous new 'O' ring seals of varying sizes and materials and none of them cured the leak.

LP steering pipe - own work

And here's where it goes and what it seals against. This is an old pinion shaft housing - the pinion shaft had rusted (like they all do), but the pipes still sealed OK right up until the rack was removed.

LP pipe to pinion housing - own work

And here's what holds it all in place. The 'U' shaped clamp on the HP steel pipe holds the LP pipe down into it's pipe socket and the ridge pressed onto the LP pipe should just about be proud of the pinion housing to allow a firm and tight fit. If the ridge on the LP pipe gets worn then there'll be a little movement with the LP pipe in its socket allowing it to leak. I did wonder if a ~1mm thick nitrile / HNBR seal in between the pipe ridge and its seat in the pinion housing would cure the leaks.

LP and HP pipes into pinion housing - own work

[white exec]

Try going for one size up on the O-ring (see Polymax in Hampshire, Viton range), and coat with Hylomar Blue.
Citroen have a habit of being rather mean with some of their OE O-ring dimensions - XM strut tops, heater matrix and even sphere plugs (or Valprex) are examples, where a fraction of a mm more in cross-section can make a real difference.

[bobins]

The green 'O' ring in the photo is already a little oversize, but it still leaked a little. The replacement pipe is holding up well at the moment so I'm hoping the problem is cured........ until the next steering component fails

[lcwin]

hi Bobbin, From your pic it is very likely there is minor corrosion and pitting on the mating surface of the O rings. Make sure the O ring mating and seat surface are smooth without any scratched marks or pitting . Any minor imperfections will results in leaks. The O ring cannot be too oversize as it will distorts and leaks. If you not sure what is the right size check with hydraulic O ring seller for advice. Hopes this helps. This kind of joints sealing is very simple and reliable .