Loosening rear spheres

[Eric Brough]

I'm just trying to loosen the rear spheres a bit in preparation for a swap-over in a week or so. I want to make sure the existing spheres are ready to come off.

So I'm doing it in the 'under pressure' manner. Car on stands, high suspension setting and trying to undo the spheres NO MORE than a quarter turn. I'm using a Pleiades sphere wrench. I want to turn them just enough to show they are free from the cylinder itself and break any corrosion.

Problem is that the cylinder is turning with the sphere and I dont know if there is anything on the BX cylinders to stop them turning all the way round. (With the GS - which I'm familiar with - there are lugs which would limit the turn on the cylinder). If the BX cylinders turned too far, I can see that the HP supply pipe would easiliy be damaged.

So question is how far will the cylinder turn with the sphere? Will something stop it turning past a certain point so that the pipework is not damaged? If so I will happily turn the sphere further to break any corrosion.

Thanks, Eric

[ken newbold]

There is a plate in there which may help it stop turning but I wouldn't rely on it, chances are you will damage the pipe first.

Try putting more weight in the boot, as much as possible, then try impacting the sphere loose a bit. Big hammer.

[AlanS]

So I'm doing it in the 'under pressure' manner. Car on stands, high suspension setting and trying to undo the spheres NO MORE than a quarter turn.

Therein lies the problem; no weight on the wheels.

I usually pump it up on high but have the stands or a couple of jacks sitting under the car as an emergency measure in case it tries to squash me. When I say "under the car" I mean about an inch or so below a jacking point of some description so if for any reason I were to activate the height corrector, the stands or jacks would catch it before it flattened me.
When they let go, they will barely turn at all but you will feel them give without screwing the plumbing around with it and at that point, I usually check the positions of the axle stands, depressurise the suspension and then see if I can easily screw them by hand. Once I can, I just nip them up finger tight and they're ready when you are to replace.
If they don't want to move with the wheels on the ground, I usually chuck a load in the boot and I have squirted a bit of oil between the actual sphere and the area the domed end touches to make it a bit easier to turn that end, after all, it's the cylinder end you're trying to jam; the domed end needs to be able to turn and this sometimes helps a bit if there's surface rust in there.


Alan S

[Kitch]

I always use drive up ramps, and then put it on high. Never had a problem.

[Eric Brough]

I was unclear. I've backed the car up ramps so there is weight is on the wheels - rather than having the wheels dangling free on axle stands.

So I'm doing just what Kitch says except that I do have a problem.

Pity I didnt do this a few days back when I had about half a ton of concrete in the back..

Thanks for your replies, guys.

[Kitch]

Is there enough room on the cylinder behind the sphere to get a friend to clamp it was water pump pliers?