Changing spheres

[Sicile]

Hi everyone,
I've recently replaced my slightly tired XM Break with a BX Break in fine condition. Of course, being 35 years old and despite being looked after, it still needs some TLC. The front spheres need changing and probably the rears too and I've hit the first hurdle. The old spheres have a date written on them (presumably when they were last changed) and it is 2020. The trouble is, I can't get them off. I've snapped a chain wrench and have now bought a Halfords spanner (something like a pipe wrench) for oil filter removal which grips well but no movement of spheres. I've tried hammering them as I apply pressure but no dice.
I don't want to push too hard as I can see the strut twisting but any ideas?

[Dave_16v]

I'll suggest this with caution but a cold chisel on the widest part followed by a good strike or series of lesser ones can shock them loose. I appreciate you say you have used a hammer but it's not clear how, if it's on the wrench, it's not direct enough.

I take it you have released all the pressure etc. ?

[Sicile]

I've been hitting the body of the sphere, thinking the vibration might help to shake the threads loose. I haven't yet released the pressure at the valve as one post suggested breaking them loose when the system was rigid at full height. I tried that and with setting at full low but no difference.

[Dave_16v]

As far as I know, keeping them pressured is for the rear to prevent them turning the whole lot and breaking the pipes connected.

I would release the pressure fully, valve as well and try again but rather than just hitting the body of the sphere, do as suggested to break it free in an anticlockwise direction for the fronts at least.

Of course, there may be other suggestions but if you're already twisting the strut area, it sounds like some other method that does not involve torque like you are applying is needed.

[Sicile]

Yes, I'll try it with the system fully de-pressurised and if necessary I'll try with a cold chisel. I've only done this once before, on my first BX and didn't have anything like this difficulty!

[Sicile]

I've tried again with the system de-pressurised but still the same result. I tried using a chisel but all I was going to achieve was a hole in the sphere! I suppose I'll have to take it to a garage and get them to do it as I don't want to break anything, unless someone has a cunning plan.

[Jaba]

I use a tool made for the job and sold to me by Pleiades. It clamps onto the sphere and with the rear pressurised you put an extension tube or bar on and it then moves quite easily to break the seal - you then depressurise and undo the sphere by hand.
Before using the tool I used the chisel method on the welded seam at the threaded end. Its brutal but it did work for me.
Refitting is hand tight only by the way.

[Sicile]

I've now tried moving the spheres at full height, normal height and fully de-pressurised. I've tried hammering them whilst using the spanner and also tried with a chisel but with not the slightest response. I have a blowtorch and a flameproof mat, would some heat help or woud the oil catch fire?

[Jaba]

I wouldn't use heat, you might do some damage to the internal seals. The answer lies in the posts above: suspension under pressure initially plus a suitable tool to grip the sphere and a length of tubing to apply sufficient turning pressure.
If the car is driveable take it to a Citroen specialist to change them.

[Sicile]

Yes, I think I'll have to take it to a Citroen person. I've now bought a chain wrench that wraps around and has a handle about a foot long. It doesn't seem to twist the top of the strut as much as my previous method but tapping the sphere or bashing the handle of the wrench still has no effect.

[Jaba]

The strut should not twist at all if its under pressure. Get a long piece of tube to lengthen the chain wrench and use your strength and weight on it. It will give if you can get the leverage. I used to use a chain wrench made for truck oil filters with a breaker bar and some square tube.
Have you tried Pleiades to buy their tool. If you are in Ashford west London you could come and pick up my tool.

[xantia_v6]

Pleiades stopped making their tools about 15 years ago, only second hand ones occasionally surface now.

In my experience of stuck spheres, if you have a tool with some leverage, lean on it as if it were a wheel brace, and give the tool a good whack with a 2kg hammer.

If using a chisel on the seam, the weight of the hammer is what makes the difference.

[Sicile]

At last! I've loosened the spheres and have now changed them. I used a chain wrench with an added extension to give more leverage but possibly an additional help was using a hot air gun on the mounting. I wrapped a heat proof cloth around the feed pipe on the top of the strut and warmed up the cast iron that the sphere screws into. It can't have expanded the mounting very much but with the added force possible with the extension bar it may have helped. Anyway, I have now changed the front spheres, so thank you to all who offered advice.

[Jaba]

Glad you got the job done eventually. Perseverance always pays of in the end.