Sphere recharging

You may argue that since the cost of spheres has reduced dramatically, there's no point in recharging them.

That's unless, like me, you resent having to spend the money on new ones.

If you're in Central Scotland and would prefer to recharge rather than throw away and renew, please drop me a line.

cheers

noz 8)

Hi
How do you test if the spheres can be recharged ????

I know one that just dont test them !!! just recharges them and seems to think its well and good !!! (just ripping people off)

That is not the case if it`s has been tested first !!!

My best mate recharges spheres in the Northwest, and he has had ones done by others that have been so called recharged but still flat due to the membrain inside being US.

I help him sometimes so I do understand about rechargeing the system he uses still use the original end caps which look better than others Ive seen with great big daft looking ends on them.

This is no way of getting at you, but I think it would help to know for other people !!!!

good luck ( the man with the big green balls)

Hi there, Guest,

I'm not quite sure what you're getting at. The sphere consists of a hollow metal sphere, a 'rubber' diaphragm and a semi-spherical plate which keeps the diaphragm edge pressed and sealed against the side wall of the sphere (ignoring for a moment the damping mechanism in the neck).

In the early days of spheres I saw one cut in half (by Westroen as far as I can remember) revealing a device at the plug hole with sharp spikes on. If the pressure in the sphere goes too low before recharging and the diaphragm touches the spikes then the diaphragm will be punctured. I presumed this was Citroen's way of making the sphere fail catastrophically once it got too old and forcing you to buy a new one.

I usually test the sphere pressure before removing the plug out of interest. In fact it's the residual pressure which I use to determine whether the sphere needs recharging or not. When recharging spheres I have sometimes seen leakage at the plug using leak detector spray. Tightening the plug usually cures the problem however, once I've had to depressurise the sphere and replace the o-ring.

The common mode of failure for a sphere is diaphragm leakage. This can either be that the diaphragm has parted company with the side wall of the sphere or the diaphragm has ruptured for some reason. There are some theories around that suggest the large number of deflections which the diaphragm performs in it's life gradually weakens the 'rubber' and it eventually fails. I personally don't believe this for reasons that would take too long to explain here. However, diaphragms do leak there is no doubt about that.

If I understand you correctly, you are suggesting there is some kind of test you can perform on the sphere against which you make the judgment whether to recharge or not. I'd be very interested in such a test. The sphere is constructed of two halves and is welded together at time of manufacture. I'd love to hear how the diaphragm is 'tested' when the only access is through the plug hole with the plug removed. I'd especially love to know how the results of this test determine the 'condition' of the diaphragm. It either leaks or it doesn't.

Personally speaking I have never managed to recharge a sphere which has a leaking diaphragm. The gas just bypasses the diaphragm and comes out the damper hole in the neck. I don't understand your claim that some people recharge spheres where the diaphragm won't hold the pressure. ( The fill pressure varies between 40 and 70 bar depending on which particular application the sphere is for.)

The 'daft' looking ends to which you refer are almost certainly the Schraeder type which are primarily used in the refrigeration industry. The reason they are so big is that there's a non-return valve built in so that they can be recharged just like recharging a tyre with air. The original plugs are just that, plugs. They have a small o-ring under the shoulder to seal the gas in. I personally re-use the original plugs. However, the drawback of this method is that the sphere must be removed from the car to recharge. The single biggest advantage of the Schraeder valve method is that the sphere can be re-charged in-situ. When you consider that the biggest and riskiest part of the job is getting the sphere off the car (especially rear ones from CX's, BX's etc where the whole strut must be removed) then you can see why the Schraeder method has it's advantages.

In terms of ripping people off, I don't charge for the service. All I'd ask for is a contribution towards the cost of the Nitrogen which I have to pay for when I get the bottle refilled.

Why not register as a user and join the forum? The more comments the merrier.

cheers

noz

Hi Noz
Well I do know that you know what your talking about with the reply given.
What I wanted to know was if you had a rig to test the spheres under presiure !!!!
that is the way to test if it can and needs chargeing !!!!!

As I said one local to me do not test them and as you said it leakes past the membrain out of the valve thus wast of time and effort, but the one I am thinking of must not know this and thinks hes recharged them or just ripps people off !!!

I think it looks better with the useual plugs in them.
Ok the other plugs can be done on the car it dont take long to remove the sphere anyway!!!

I dont understand or might just not got what you say about CX BX Etc rears haveing to take the strut off.
No need to take strut off to remove the sphere !!!
If you send to fully up and put your chain wrench on to slacken Not Remove them let down to bottom the sphere will just spin off very easy

I was not saying you ripp people off in any way just like to know for others to benofit from knowing that there are people that do know what is the right way of doing it right

I might register in the forum but I just found it in the last few days so just testing it out at the mo see how good it is

I do have XM 2.1td & 4 Bx`s 1 xantia so must be use to the systems by now. I best not tell you how many my mate has lets just say over 30 coming out his ears with parts so I never get stuck for parts EEEEEE

Hi guest,

no offence taken.

The problem with BX's and CX's is that the sphere is trapped between the end of the strut and the chassis. The Xm on the otherhand has the sphere sticking out from a hole in the chassis in mid air - very easy to get to using the technique you describe. The CX rear struts must come off to replace the sphere, there's no choice in the matter. That's where the job usually turns into a nightmare. There's a mild steel clip which passes through a hole in the alloy strut and also through the end of the strut plunger. The alloy corrodes because of the disimilar metals and the pin gets stuck. The job is nightmare proportions if you can't get that pin out.

That's where the big advantage comes in replacing the plug with a schraeder valve and obviates the need to remove the sphere.

I could be doing with a couple of parts for my Xm's, so if your mate is in the business of selling parts then I'd be interested.

Cheers

noz

Hi Noz


Yes if you let me know I will see if I can help you and ask my mate for you ASAP
He useualy keeps the parts for his customers if just want a second users part fitting rather than spend on new parts as he will only fit genuine parts !!!!

I will give you the reason why I do the same bought some bottom wishbone bushes cheap ones had them on for about 4 weeks and were US, got the genuine ones after not much in the price still going strong today so its not worth puting cheap parts on as it costs more in the end !!!!

Hey I know thay can be a pain in the arris Give them a good plus gas first if you can a week before and a few days after !!!!

Had the rear cylinders leak from the sides through the ally just a pin prick makes it look as if the seal on the sphere as gone as they collect all the sh1t in and people never think of power washing them out now and then (would be a good thing to do once in a while) I do it once every 4-6 weeks sooon collects in there.

Got the XM about 4 weeks ago wife hates Citroens Days weork had it MOTed now cant keep her out of it Good job she cant drive (apart from me up the wall) Id never see it

Off now back to bed