I agree that at current prices it's hardly worth the effort of getting spheres recharged, particularly as you're never sure about the condition of the diaphragm. I beleve it's different in Oz where new spheres are hard to come by and expensive.

There are two, and only two, spheres on XMs that don't have dampers. Common to all models is the accumulator sphere which is fitted to the pressure regulator and is the foremost central sphere. The other, fitted only to cars with anti sink, is the so-called antisink sphere, more logically described as the rear brake emergency accumulator. This is hidden above the rear silencer on the left hand side and has no effect on suspension.. Because these two spheres have no damper valves, there will be no reference to damper sizes in the AGF catalogue.
All the suspension spheres; front left and right strut spheres, central front hydractive sphere, rear left and right trailing arm spheres and rear central hydractive sphere; have their damper sizes listed.

Derek

You've completely thrown me now Derek.

I have in my possession three used spheres and none of them have damper valves in them. So maybe the two that were replaced yesterday were the correct centre spheres? I'll post the part number of one of the used ones when I get home from work in case anyone can recognise it.

Try Leek Motors, Harper Rd, Coventry. He has all the kit and always does my hydaulic work nowadays. Contact Nigel Leek on 07899 986603.

Sorry Dave, my post above was a classic example of engaging typing finger before engaging brain.

All the suspension spheres operate through damper valves, but... and this is the big but that I overlooked... whilst the corner spheres have built in damper valves, the centre hydractive spheres have their valves built into the control blocks that they are screwed to so there are none in the spheres themselves.

Hangs head in shame. If it's any help I'll look up the full details and post them later on.

Derek

Hi DerekW/demag/et al,

The two centre hydractive spheres do not have dampers. They look like and are just accumulators. The dampers are built into the hydractive block instead of the sphere neck. So your 3 spheres without dampers are likely to be the main accumulator and front and rear hydractive spheres.

I also do not conform to the belief that diaphragms 'weaken' over time as is a commonly held view. They hardly do any work at all. The pressure is balanced on both sides of the diaphragm at all times. They do however lose presure by osmosis over time. A longer lasting, triple layer, diaphragm is available with a lower permeability to the passage of Nitrogen molecules through it. I believe those spheres are characterised by three dimples on the top around the fill plug.

I have successfully recharged my own spheres for over 15 years now since I designed and built my own rig. For those unable to do it themselves I can probably agree with the financial balance being tipped in favour of new spheres versus recharging.

Cheers

noz

oops - posts crossed in the ether

Yes one of the removed spheres has three dimples around the plug. I can't tell on the other one cos its slightly rusty at that end. I'll check later.

The part number on the one with the dimples is: 96 181 131 (5-090-DT) Don't know what the bit in brackets signifies. Maybe DT stands for Dimple Top

Well I finally changed the front centre for one from GSF and its now a lot softer, although I might do the wheel spheres as well cos I don't know their history and I think it could be softer still.

Do I have to drop the exhaust to change the rear centre or can I wangle it?

Dave,
You enquired about firms in the midlands, rather belatedly, and for general interest there is westroen-spheres.co.uk. I found them to be excellent and they will will either carry out the work for you or supply spheres clearly marked and with 3yr warranty.
Robert.