| Author | Message | |||
     Rob. Smith Yet to post message Username: ro80rob Post Number: 1 Registered: 8-2007 |
I have searched the postings, but cannot quite find the answer I need but I'm positive somebody will have the know how. I need to replace the accumulator spheres. I have only 12 pumps on the brake pedal before I get the warning lights. I've had a look under the car for a quick appraisal, and I've looked in my manual. It seems that to get the rear sphere off, I will need to remove the front accumulator to get some room to unscrew it. I was wondering if this means I have to disconnect the hydraulic hoses for the front accumulator, or can I undo the front accumulator from its mountings and ease it sufficiently out of the way whilst I get access with my ebay purchased sphere removal tool to get the thing changed. Any advice here would be very useful. I really don't want to have to bleed the whole system especially after I have seen the tips and tricks on the forum to change the spheres without much fuss at all. Also, will standard Citroen CX spheres be adequate. They are cheap enough in the aftermarket. Cheers... Rob. | |||
| Paul Yorke Prolific User Username: paul_yorke Post Number: 147 Registered: 6-2006 |
Hi Rob, Just remove the front sphere, then the rear. They are pretty much self bleeding. Just run the engine for about 10 mins before you apply the brakes. You need 75 bar spheres. (Message edited by Paul_Yorke on 02 May 2008) | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1380 Registered: 4-2003 |
As Paul writes, you must remove the front sphere before removing the rear one. 1. To be sure that the system is 100% depressurused, open the bleed screw for a short while then close it. See the attachment with the arrow pointing to the bleed screw. There is no fluid loss as the bleeding is internal to the system. Now remove the sphere. 2. After fitting the new sphere (replace both for good measure), run the motor until the system is pressurised then stop the motor. Open the bleed screw again until the pressure has almost gone again, and close it. Job done. Although the system is basically self-bleeding in this circuit, it is worth the 30 seconds to do this positive bleeding for which the system was designed. As stated, there is no fluid loss and it is a trivial operation. That way you may be more confident that no air enters the brake or levelling systems. On CX spheres, if they are physically the same size and 75 bar, OK. However, secondhand or old stock are are unwise. We landed a case of proper new spheres last year for club members in Australia from the UK at not much more than £20 each for the proper new ones (plus shipping and GST of course, but you pay that wherever you buy them), so why bother with dodgy ebay purchases or aftermarket spheres unless the aftermarket ones are new and specifically for our cars ? RT.
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| Neville Davies New User Username: nev_davies Post Number: 8 Registered: 9-2006 |
On the subject of spheres I changed both last year on my spirit.I've noticed recently No"2 system takes longer for the pressure light to extinguish and also comes on sooner on test ie.No1 system takes a lot of pumps but No2 only about 20 pumps for the light to come on could this be a sign of air in the system? The pedal feels good and the brakes appear fine. Nev | |||
| Rob. Smith New User Username: ro80rob Post Number: 2 Registered: 8-2007 |
Hello OK I've been underneath (jacked the car well up) and had another good luck. I even took a couple of photos which I've included here (I hope). There is not enough room to unscrew and remove the rear sphere as it stands. I can't even get my finger inbetween the end of the rear sphere and the accumulator body of the front. However, The metal pipework to the front unit is long and I reckon that if I undo the two bolts holding that accumulator body to the block (actually its on a steel bracing plate attatched to the block), I can ease the front accumulator away and generate enough room to get the rear sphere off without undoing any pipework. I can't see any other way to succeed with this. Cheers... Rob.   (Message edited by david_gore on 03 May 2008) | |||
| Paul Yorke Prolific User Username: paul_yorke Post Number: 149 Registered: 6-2006 |
Rob, don't know what to say. I can't remember taking a valve off to change an accumulator but maybe the bracket is bent or something. All I can suggest is having a go and seeing what happens. If you need to remove the mounting bolts, I'm sure it will move enough without undoing the pipes. | |||
| Rob. Smith New User Username: ro80rob Post Number: 5 Registered: 8-2007 |
OK I think/am pretty confident I can move the front unit far enough over to get at the back one. So back to the spheres. After considerable homework, I now know that the Citroen CX front suspension spheres from the saloon/estate have the 500cc volume and 75 Bar pressure required. However, being suspension spheres, they are fitted with a one way valve and a restrictor. The valve lets the fluid in quickly as the suspension is squashed (i.e. going over a bump) allowing the wheel to rise into the wing aperture. However on the rebound, the valve closes, and the fluid is allowed to escape through a 1.9mm hole. This provides the damping effect for the suspension. I am not 100% sure that this would be a problem. In the RR system, the pumps pressurise to the appropriate pressure. This would occur through the valve. This would then mean the only way that fluid could leave the sphere and power the brakes/operate the self levelling is through this 1.9mm hole. I reckon that actual fluid usage is pretty small for the brakes, and the self levelling is so slow (and the pressures so high) that this sphere would probably work OK in this application. However, not being 100% sure, we move onto the next candidate. This would be the hydractive centre sphere from the XM or Xantia. This is a 500cc 70 Bar unit that has no valves or restrictors (as per a normal accumulator sphere). The main problem with this unit is obvious in that it is 5 Bar down on the specified brand new requirement. I am not sure what this would exactly mean in terms of operation. I guess that the pressure in the spheres falls steadily throughout their working life, ending up considerably below 70 Bar at the point they need changing. Anyway, this is all just the facts. I am after an opinion from you on this. Oh I forgot to mention that the XM/CX spheres are only £19.50 + VAT each brand new as opposed to Flying Spares £35 + VAT + postage each. There appears to be no replacement for the rear suspension spheres, being such a low pressure (18 Bar). The lowest available Citroen spheres being 30 Bar, and it seems not possible to 'let a little gas out' to get the pressure required. Flying spares want £40 + Vat + Post each for these. Any thoughts?? Cheers... Rob. | |||
| Paul Yorke Prolific User Username: paul_yorke Post Number: 150 Registered: 6-2006 |
Hi Rob. Yikes . . . . before you do yourself an injury . . . Buy a set from Flying spares, there will only be one lot of postage as well that way. I can do a full set for £130 + vat and postage if you're interested. Remember that these are safety critical parts filled with 1000 psi gas, not something to start poking around with! | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1381 Registered: 4-2003 |
There are lots of reasons above to stay with the proper spheres. Given that new Citi spheres are no cheaper than proper ones when on offer from Introcar of Flying Spares. We paid £15 for main (brake) spheres and £20 for rear (suspension) spheres less than a year ago. That is £70 for a full set, seals thrown in free, brand-new and not old stock. This is a no-brainer. | |||
| Rob. Smith New User Username: ro80rob Post Number: 6 Registered: 8-2007 |
Hello Paul/Richard I think I am persuaded that I should go with the genuine items, though I don't see any deals like you got Richard. It seems that Paul has a good deal for me for genuine/correct parts. I am interested in your offer Paul. Could you contact me (via the private message if necessary) telling me exactly how much you require for the 4 spheres Plus postage plus VAT. I can pay you how you wish. Paypal would be great, and I understand that a small increase to cover paypal fees would be incurred. I am happy to go with cheque also. Its up to you. Cheers... Rob. | |||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1382 Registered: 4-2003 |
It's a pity you didn't join in our bulk buy of spheres last year. Everyone thought we were mad. Don't expect genuine Crewe branded spheres from Flying Spares. Mind you, they may be the correct spheres by specification and will be probably just as good. Were there enough takers, we could arrange another bulk order at stunning prices. That also applies to disc rotors and many othe key items. RT. |
Accumulator Internal Bleed Screw