Xantia hard rear!

MikeT · Post by **MikeT** » 11 Mar 2008, 17:41

Interesting debate! I wonder how the lone mechanic or even Citroen themselves accomplish removal?

simoncanfer · Post by **simoncanfer** » 11 Mar 2008, 21:30

Thanks so much for all your help!

Nearly there - the failed sphere pressurised OK once I had realised that the "button" on the end of the sphere was in fact a sealing screw. This is where I had lost my LHM from.

I tightened the screw, jacked the car up to max and settled it on axle stands. Lowered the suspension control and got the sphere off with a lump hammer and chisel

) An old oil filter chain wrench did the rest.

I find it hard to believe that the sphere screw and associated O ring seal the sphere effectively - can anyone comment? I suspect there's another non-return valve inside that has failed. Not that it matters...

3 days into ownership and 2 litres of LHM - I hope the consumption rate drops now!!

slim123 · Post by **slim123** » 11 Mar 2008, 22:10

Simon.

The filler plug and it's "O" ring seals the gas inside the sphere at 30- of pressure, there is a rubber diaphragm inside the sphere that seperates the gas side from the fluid side.

Fluid coming from the filler plug tells you the the diaphragm has burst and the sphere has filled with LHM, this now makes the sphere scrap metal, it will need fixing with a new one.

When replacing it is good practice to replace them both, ie an axle set.

Regards
Slim.

juraj · Post by **juraj** » 11 Mar 2008, 23:55

Monkeyfeet wrote:Yep, got to vouch for the full system pressure with the missus, the kids and a neighbour or two sitting in the boot method. Also agree very much with the only needs an eight of a turn bit, too.

Yes, I have good axle stands!

hmmmm

so what tool do you use to undo the sphere? even though i have a heavy duty strap wrench at very high tourque to starts to slip,

bye

Post by **myglaren** » 12 Mar 2008, 07:50

The guy that does mine has a gargantuan pair of 'pincers' about four feet long. Makes very short work of them.

I stood and watched him do the rears on my Xantia, took him 10 minutes from start to finish, including lifting it on the hoist, dropping it back to the ground and topping up the LHM.

Post by **RichardW** » 12 Mar 2008, 08:15

Tools:

Heavy duty 'gas pliers' as noted above; proprietary 'band' type sphere remover; home made sphere remover (bent threaded rod and angle iron); hammer & chisel (never fails!).

Rears that have been exposed to road salt for 6 or 7 years usually need a good 'talking to' before they will come loose 8)

juraj · Post by **juraj** » 12 Mar 2008, 09:58

yep the rears i did had lots of fluffy corrosion on the aluminum cylinders, and hammer chisel never has failed me yet,

but there is a guy selling a home made tool on ebay im sure you are all aware of, might make my own back home,

bye

simoncanfer · Post by **simoncanfer** » 12 Mar 2008, 11:53

I'm thinking aloud so by all means ignore - but has anyone found a way to prevent corroded-on spheres then?

e.g. Copper grease? Waxoyl? WD40 regularly?

It seems to me the threads we're battling against are internal to the hydraulic system, so I'm not sure copper grease could be recommended - maybe a coating of PTFE-containing spray (GT85) prior to fitting may help.

As the threads are internal, WD40 on the outside wouldn't do much good.

Perhaps its a galvanic corrosion - steel sphere against aluminium body. This must be a common enough problem to have a standard solution in the hydraulics industry I'd have thought...

AndersDK · Post by **AndersDK** » 12 Mar 2008, 19:09

simoncanfer wrote:I'm thinking aloud so by all means ignore - but has anyone found a way to prevent corroded-on spheres then?

e.g. Copper grease? Waxoyl? WD40 regularly?

It seems to me the threads we're battling against are internal to the hydraulic system, so I'm not sure copper grease could be recommended - maybe a coating of PTFE-containing spray (GT85) prior to fitting may help.

As the threads are internal, WD40 on the outside wouldn't do much good.

Perhaps its a galvanic corrosion - steel sphere against aluminium body. This must be a common enough problem to have a standard solution in the hydraulics industry I'd have thought...

You are thinking absolutely right - but not reaching the correct conclusion 8)

As the sphere threads are completely immersed on the wet side of the sphere seal, the threads are completely soaked by LHM. Thus will never corrode

Its been discussed MANY times here and on other Citroen forums.

The problem is NOT corroded sphere threads

Its the sphere square profile rubber seal that makes the sphere stick solid on to the cylinder !
The seal sort of "vulcanises" on to the sphere seal surface, and makes the sphere next to impossible to crack loose.
As the rear spheres have a real hard life exposed directly to road dirt, water and winter salt, rust will very slowly form and over time "grow" in under the rubber seal, making the seal stick even harder.
This can easily be prevented by a smear off underbody coating, copper grease or aluminium paste on the sphere seal surface - when fitting it first off.

The seal is there to provide a POSITIVE high pressure seal.
Any thoughts out the line of WD40'ing or anything like that is therefore NONSENSE