Ruptured sphere removal - high pressure risk ?

[charentejohn]

I read somewhere, but now can't find it, about a 'dead' sphere storing high pressure so could be a blast of LHM when removed. True or false ?

Just doing the rear spheres (so I am under them) as the rear suspension went hard, this is a sphere that's gone but I don't know which one.
I have both spheres started, not too much pressure needed to crack them open, and an now just undoing them. However the first one is stiff when removing, so mow undone about 1-1.5 turns and no LHM but needs the removal tool to move it, can't undo by hand.

Is this correct, that it should be resisting. I have the car on low, depressurised with engine running, now engine off so I would have thought even a ruptured sphere should now have no pressure in it ?

[addo]

Leave the back on the ground, press the brake pedal hard a few dozen times.

If you are throwing away the spheres, unscrew the bung at their opposite end - keep a rag over the jaws of your multigrips, and wear eye/ear protection in case you crack the "good" one.

When one is loose, the other will follow readily.

[charentejohn]

Thanks Addo, the spheres don't have a bung in them all sealed, but I will do the brake bit before continuing.
My car is the really simple one, hydroneumatic, 6 spheres, no tricky bits, I hope.

Just a bit worried that I was going to be treated to a blast of high pressure LHM at some point, a small 'splat' and trickle I can cope with.

One other question, I undid the spheres as per Old Guy's instructions including 2 bags of cement in the boot to add weight.
This is to avoid twisting the rams and damaging pipes. Where are the pipes I could be damaging ? Only ones I can see are at the end where the sphere is, are there any out of sight inside ?
I undid the spheres 1/8 turn on high pressure etc but just concerned I may be twisting them now ?

This is my first timke doing any suspension work so just a bit cautious etc. Once I have done this I will be fine, just don't want to make any costly mistakes.

[Hell Razor5543]

The spheres themselves don't hold a lot of fluid (about 0.5l), but if the diaphragm has ruptured then it can still be under a bit of pressure. When the sphere is removed it can pretend to be a water pistol. I had this happen on my previous Xantia.

One way to reduce spillage is to use plastic bags. When you can turn the sphere by hand, pop a bag over it so that it can drop in once it is off the cylinder.

[charentejohn]

I had forgotten about the plastic bag trick, I had cloth wrapped around them and a dish underneath, but a bag would catch spray better as well.

[CitroJim]

The only thing I've seen with ruptured spheres is they hold a lot of LHM inside them which is not displaced when the system is depressurised... 400cc of LHM goes a long way and makes quite a puddle on concrete I find.

This can be messy in the case of accumulators and spectacular in (especially in the case of hydractive) corner spheres as they can fire a needle-thin jet of LHM at some velocity for a considerable distance for some time!

I once removed a ruptured front and painted a line of LHM all up next-door's wall

[charentejohn]

So apart from a lot of LHM I should expect a fair bit of pressure from the damaged sphere regardless of depressurising the system ?
With any luck I will be removing the ok sphere first which may help, 50/50 chance

[Hell Razor5543]

Another way to limit any spillage is to use a coke bottle with the top cut off. Pop the sphere thread down into the bottle. If you are planning on changing the LHM fluid you can then use the bottle to protect the filters/pipes that normally are in the LHM reservoir.

[charentejohn]

This is becoming 'spherewatch live' as I have just did as suggested and now have a steady drip/slow stream of foamy custard coloured fluid.
Interesting as it is neither green or brown.
I will let it drain a bit then remove completely, currently running into a cut down bottle.

[CitroJim]

It starts off green and goes through various shades of yellow before turning brown John...

[charentejohn]

Another slight problem, how easy is it to cross thread these ?
I am trying to fit the new spheres and they don't want to go past half way, 2-3 turns.
Should I force them ? Currently can only do them so far hand tight and about another half to go but should I need a tightening tool to do this or will I be damaging the rams beyond repair ? As well al leaving a bad seal anyway.

The ram is moving so I have clamped it in position so could apply more force, just aware of the warning not to bend the incoming pipes, which seem to be inside the housing so I can't see them only feel them.

[Hell Razor5543]

The spheres should not be done up past hand tight, as they will get tighter over time. I would be inclined to check that the threads are clean (as dirt will cause them to bind).

[CitroJim]

It's very easy to cross-thread rear cylinders as they are made of soft alloy. If the spheres don't screw home easily you must determine why..

Often there's damage on the sphere threads and this can happen of the sphere gets dropped and there's no thread protector present.

Pleiades have a die to clean up damages sphere threads... And a tap to clean up damaged cylinder and block threads too...

[charentejohn]

Damn.
The spheres have protectors but the threads are quite 'sharp'. I tried the other sphere and it is the same so I think I have cross threaded.
I will try the original sphere to see if it fits, if so it must be bad threads on these.
I will also remove the other side and see if I can fit one there.

[charentejohn]

First the good news, the rams aren't cross threaded, yay. I put the old spheres in and they fit perfectly, sadly one or both is no good.

I bought 'Lizarte' brand ones as I assumed they were good but it looks like the thread is naff and jamming on the ram thread after about half way in.
Any idea what these threads are as I may be able to get a nut from a local place and work on them a bit. Maybe doing this will remove the burrs and bad bits without needing to damage the rams.

Anyone used this brand before or any suggestions on thread cleaning.
Sadly, as ever these days, car is dead in the water until resolved. It shouldn't be this way, having to fix someone else's problem before I can get on.