Xantia Hydraulic Pump Rebuild

[DHallworth]

I steam cleaned the hydraulic pump to get rid of all of the crap that was on the casing tonight and then started to strip it down to replace all the o-rings.

When I took the end cap off the pump to replace the big seal at the end I noticed that there was a torn paper type gasket between the two parts.



This one had torn when the two parts of the pump came apart and it looks fairly scruffy now. Unfortunately Citroen don't even mention this part on the parts diagram. Anybody got any ideas or suggestions?

Also, under the circular caps that you use a torx bit to remove the old green o-rings were brittle and stuck to the pump body. When inserting the new ones, do you just sit them loose or do you push them into the recess on the cap before screwing it back down?

Thanks!

David.

[DHallworth]

Have just ordered some gasket paper off eBay so I can attempt to make a new gasket for it. Fingers crossed!

David.

[CitroJim]

Hi David, I'd place the new green O rings on the very ends of the circular caps. If you place then in the recesses there's a risk they can be damaged while screwing the caps back in...

Lubricate them with a smear of LHM too..

[Mandrake]

I don't think that paper gasket is essential David - I had the same problem with mine, a torn disheveled piece of paper half stuck to each piece when I took the end off, and no possibility to get a replacement.

I scraped both surfaces clean to remove any remaining fragments of the gasket and put it back together with the new o-ring and I've had no leaks. When you think about the pressures involved a flat face paper gasket isn't going to hold anything back! It's all done by the large o-ring. I'm not even sure why they bothered to fit it.

Funny thing is when I did the pump on my 2 litre Xantia years ago I didn't notice any gasket being present! Either that model of pump didn't have one, it was missing, or it stayed stuck to one surface without tearing and I didn't notice it.... That one didn't leak afterwards either.

[sparksie]

Could it be more a spacer, rather than a gasket?
In water pumps, in the marine world, theres often a paper "gasket" that's essential to prevent the impellor sticking. Sometimes there are two, when the impellor has been replaced and the new one is a couple of thou fatter than the old one! These are in addition to a neoprene "O" ring, which keeps the high pressure water in!
Could the hydraulic pump be similar?
I've never had anything to do with one, so could be WAAAAY off the mark...

[Mandrake]

Well, there are no impellers and no physical contact between the cup and anything inside except the shank where the o-ring is, so I don' think its important. Below is a picture of the standard Xantia pump (not the V6 version) but I believe that the right hand half of the pump is still the same:



The gasket in question is at point 2 on the diagram, and it is extremely thin to the point that its easy to overlook that it's even there. There is a big fat o-ring right next to it which does all the work of sealing it.

[DHallworth]

Well I've ordered the gasket paper now so I'll wait till it's arrived and then it's going back exactly as it was when I took it off.

Here's how I fitted the green washers to the torn caps:



I took one of them out again to take the picture tonight and they're sitting exactly where they were when I dismantled it last night so am quite happy that it's right.

I've also bought a sphere seal as per one of Simon's previous posts to use at the other end of the pump, that way I know that every seal in the pump is new.

David.

[Old-Guy]

David, I go along with your view. If a paper gasket was fitted, there was a good reason. Manufacturers don't waste money (not even a cent) on unnecessary components, indeed they employ 'value engineers' to find ways to shave costs any way possible - often at the expense of longer-term reliability.

[KennyW]

David,

I don't suppose you would have any objection if I had this to the Xantia plumbing thread

Kenny

[DHallworth]

Not at all Kenny.

David.

[addo]

A thin smear of oil resistant RTV where the paper was, will suffice.

The shaft seal is the trickiest; fortunately the pulley is not insanely tight a press fit. If you renew this one measure the pulley position on the shaft first!

[DHallworth]

Hi Addo,

That's the only one I'm not going to change I think. It appeared to be dry in that area so I think I'll leave to it.

David.

[FRJoey46]

Hello all,I'm throwing myself in the mercy of you helpful chaps once again.I am now half way through reconditioning my hydraulic pump with a 30 euro set of O-rings.2 problems so far...the biggest being HOW THE HELL do i unscrew the six grub nuts and the two more hefty large nuts??!! I'm a fairly strong guy yet even in a vice using all my strength can't undo any of the nuts. Second problem is I don't know where two of the I rings even go . I attach a picture showing the old ring I need to replace but in addition there is a larger one and a strange kind of collar washer also pictured, I'm really thankful of all or any advice please guys. Cheers
P.s pushing on through 356,000km!

Old o ring

Old o ring replacement,larger o ring and collar type washer *thingy lol

[ekjdm14]

Afraide I can't help on the larger of the O rings, but the "collar" looks very much like a standard oil seal that would be used to seal a rotating shaft. On that basis I'd say it was the shaft seal that would go in behind the pulley (the one where you need to press the pulley off to replace).

Having not resealed a pump before I can't say this with 100% certainty, but it seems right to my mind that's what it'd be.

[CitroJim]

A good tip to help undo the Torx socketed plugs is to give them a sharp tap with a hammer before trying to undo them... They will be tight so use a good Tox bit and a breaker bar...

Ditto the 19mm hex headed ones... Be careful as under them is a ball and a spring that can easily go walkies...