XM ACCUMULATOR SPHERE

Linegeist · Post by **Linegeist** » Wed Feb 17, 2010 12:53 pm

They are 'handed' - diesel pumps go on the left of the engine while petrol pumps on the right (as you sit in the driver's seat).

Post by **Tim Leech** » Wed Feb 17, 2010 1:23 pm

Thanks Bob, I did note they were fitted in different places but wasnt sure if that made a difference to the way they operate.

So has anyone got a petrol HP pump, new or known to be excellent used?

MULLEY · Post by **MULLEY** » Thu Feb 18, 2010 8:06 pm

What about that posting about the gti 8valve that was being broken as part of scrappage, contact the breakers, they may sell it to you for peanuts??

Aerodynamica · Post by **Aerodynamica** » Mon Mar 01, 2010 8:29 pm

Thought I'd resurrect this because I reshimmed the pressure regulator on Saturday and already not improved hydraulic performance.

I now realise that with the PR maintaining a higher cut out pressure that the accumulator will be more compressed gas wise. All this talk of Xm center spheres has me thinking that it would be interesting to fit a bigger sphere of slightly higher pressure as an accumulator to hold a larger reserve.

So is the XM center front a 500cc, no damper, rest pressure of 60bar or over?

jonathan_dyane · Post by **jonathan_dyane** » Tue Mar 02, 2010 12:01 am

Aerodynamica wrote: So is the XM center front a 500cc, no damper, rest pressure of 60bar or over?

Actually it's 500cc, no damper, rest pressure 70bar.

cauchoiskev · Post by **cauchoiskev** » Tue Mar 02, 2010 12:00 pm

Roverman wrote: PAS works fine, as does everything else once its running, just that the rear end sits down quickly and takes a while to rise when cold. The accu spheres tired anyway so though about fitting a bigger one.

Strangely enough, even though it will keep the back end up a bit longer, fitting a bigger/new accu will probably make the car even slower to rise, because the pump first has to fill the spheres up to pressure before the car budges.

The back end symptom could be old LHM, or leaky rear struts, or most likely a tired doseur. Not a big problem unless the braking is affected, in which case it must be well gone.

If your PAS is fine, for me that is the indisputable proof that the pump is working perfectly, frankly, I would leave it well alone !

Aerodynamica · Post by **Aerodynamica** » Tue Mar 02, 2010 8:30 pm

Well, I have just fitted the XM centre sphere to the regulator of the CX and I must say it seems to have made a large improvement to the action of the steering and suspension.

I should say that the sphere alone will make no odds but recently I reset the regulator to cut in and out at a higher level - raises the overall pressure you see, the effect being that the gas is more compressed in the accumulator and holds a larger volume of LHM under a higher pressure. The XM sphere being both 500cc and higher initial pressure of 70b needs a higher pressure of LHM to compress it to a high proportion and so works really well with the reset regulator.

End result is lighter steering, and with the engine off the rear suspension will relevel twice (almost 3 times!) under its own pressure. Front will do it once. Before it didn't do it at all with a normal accumulator fitted last Sept.

Anyway, just FYI!!