Rolls-Royce and Bentley Forums banner

1 - 20 of 25 Posts

·
Registered
Joined
·
77 Posts
Discussion Starter #1
Hello
I want (need) to replace the spheres on my accumulators. I've done the brake pedal pump test, and can only get 12 pumps before the warning lights come on. This is not a good situation. I understand that 30 pumps is a minimum and 60 pumps great.
Anyway, has anyone got a feeling which spheres to use. I reckon that I can fit normal Citroen CX type spheres (as these are the correct era) on the accumulators. As for the rear suspension ones, (assuming I go the whole way), I need to get proper RR ones, as I understand they are set to a special low pressure (~18 Bar), which is not available 'off the shelf' for the citroen.
Also, does anyone know what the difference is between the Citroen XM and the CX accumulator spheres?

Cheers... Rob.
 

·
Registered
Joined
·
9 Posts
Just had mine done and I confess that I took it in as the pumps were leaking as well.
 

·
Registered
Joined
·
77 Posts
Discussion Starter #3
Forgot to mention, its an 89 Turbo R.
Now then
I've had a look underneath (and looked in the manual). It seems that it is necessary to 'remove' the forwardmost (front I guess) accumulator unit to even stand a chance of unscrewing the sphere from the rear accumulator.
Now
Do I have to remove this. or can I just undo it and move it out of the way a little to get the sphere removal tool on it and the sphere actually off.
Any ideas here?. I don't know if my situation is tighter than in the Spirit, as these items would have been on the other side of the block. My problem is the turbo, which has resulted in a possibly more cramped installation on the left hand side of the block.
Anyone any experience doing this?

Cheers... Rob.
 

·
Registered
Joined
·
58 Posts
Spheres

Hi Rob!

There is a good HOWTO available on the Australian forum. I've seen and read it but can't tell you the exct link. I'm afraid you will have to start your own search. I'll come back here in this thread, if I should run across this the coming weekend.


Regards JimKnopf
 

·
Registered
Joined
·
244 Posts
ro80rob said:
I've had a look underneath (and looked in the manual). It seems that it is necessary to 'remove' the forwardmost (front I guess) accumulator unit to even stand a chance of unscrewing the sphere from the rear accumulator.
Hello Rob,
No, it's not necessary.
You put off the first sphère and after the second one, with a facom tool for oil filters.
If the previous work has been good done, it's very easy to change the sphères.

A good done is to tighten the new sphères only with his hands.

A good idea is to put down the rear of the car by occur on the hight régulator with a screwdriver, before shuting off the pressure in the oil circuit, on the 2 régulators.

Best regards
Bernard
 

·
Registered
Joined
·
16 Posts
I just replaced spheres on my 1980 Silver Shadow II,
IMPORTANT:
Every time you must replace spheres, you MUST also remove pressure valves (adiacent to spheres) and rebuild them, there's an appropriate rebuilding kit offered by Rolls Royce dealers.
This is important because the new highly pressurized spheres risk to explose, the old dried seals on pressure valves with consequent oil leaking.
When I did it on my 73 Shadow, an other fault occourred:
the rear height control valves was corroded by old (never changed) brake fluid, both them exploded on freeway and had to replace the group.
Also check rubber hoses and eventual oil leakings from rear shock absorbers.
ITS ANYWAY INDISPENSABLE ask to an OFFICIAL Rolls Royce-Bentley mechanic to replace spheres because must be purged the entire brake fluid, replaced with new one (Castrol RR 363 only on Shadows, Corniches, Camargues and Ts and MINERAL OIL on later models) and test each circuit pressure to obtain the desired brakes power and height control fonction.
REMEMBER ALSO:
RED WARNING INDICATORS ON DASHBOARD must be switch off when engine running!!!! BUT often not so good mechanics removed bulbs on dashboards to resolve the fault! So check also warning lamps functionality!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 

·
Registered
Joined
·
7 Posts
To answer one of your first questions - the accumulator spheres on green-juice cars are identical to those used on Citroen CX, BX, GS and late DS (and possibly some of the newer ones but I don't know about those). They are available in UK from GSF for about 20UKP - no exchange.

Similarly HSMO=LHM.

The rear suspension spheres are not equivalent to any Citroen sphere, as far as I know, but I would love to know different.

Hint: as someone has said, tighten them only hand tight. Don't spin them down to a stop because the impact of stopping the sphere will lock it on too tight. If it leaks under pressure the O-ring is not seated properly.

Hint: if you can't get it off any other way use a chisel on the outer circumference. Since you are going to throw the old one away, who cares. Citroen specialists (I don't necessarily mean Citroen agents) sell VERY robust tools for removal - the message about fitting them hand tight has still not reached everyone on the garage world.
 

·
Registered
Joined
·
77 Posts
Discussion Starter #8
Hello Alan

You are correct in that the sphere is mechanically a citroen sphere.

However

The only Citroen sphere that comes close to being correct is the Citroen CX front suspension sphere. This has the same 75 Bar pressure as the RR unit.
But...., it is not an accumulator sphere, so it also has a valve and a restrictor hole (I did my homework on this little lot before I bought replacements). This provides the sphere with the 'shock absorber' effect. The valve opens to let the fluid in as the suspension piston pushes fluid up into the sphere (as you go over the 'bump'). The fluid can only escape through this 1.5mm hole as the spring re-bounds after you have traverseed the 'bump'. This slowed down flow stops the oscillation that would occur otherwise.
Use of this CX sphere on the RR accumulator system is debateable. Do you consider that the sphere would need to pass fluid out to the brakes at a rate quicker than can be supplied by the 1.5mm hole?. That is the question, and not having designed the system, its not possible to be sure.
Personally, I would guess that it would probably be OK, but there is always that element of doubt, so the smart move is to buy the right one and accept the price doubling over and above GSF's prices.
The rear spheres are only 15 Bar pressure and definitely a RR special pressure, though mechanically its the same item.
As for the fluid, I use Citroen LHM. Its available much more readily, though I do decant it into the original Castrol bottle, as that fits in the holder in the boot.
I take on board the 'not overtightening' of the spheres on re-fitting. I bought a tool off Ebay to undo the stubborn ones. As I said earlier, my accumulator spheres are mounted awkwardly, so I think we will have to demount the lower accumulator to get the upper sphere off. We reckon we can get sufficient flex on the pipes on the lower accumulator unit to get enough room to do the upper.
I won't be re-building the whole accumulator though. The car has only done 55k miles. I didn't see any special tips on the Australian site, which is an excellent resource for the DIY mechanic.

Cheers... Rob.
 

·
Registered
Joined
·
7 Posts
Aha!

Rob, the Citroen manual says the accumulator sphere is nominally 62.5 bar and my Spirit manual says "60 to 64 bar". It may be higher for later cars - I don't have a Turbo R manual - but the difference is trivial anyway because the working pressure is determined by the regulator blow-off setting. If a lower pressure sphere is used a slightly larger volume of oil at slightly faster pressure drop-off would be available in emergency "no-pump" situations, which have a huge margin of safety.

If you want to use a suspension sphere, drill out the hole. It doesn't have to be huge because the rate of flow is very small - think of the cross-section of the pipes. Take precautions to stop filings getting into the fluid and don't drill through the diaphragm plate. The restrictor is only a couple of mms deep. I use this technique to tune the suspension characteristics of my classic Citroens, and so do other people.

Regards from Alan D.
 

·
Registered
Joined
·
9 Posts
Replacement Spheres

Everyone tries to find a cheaper way to go. In the US, we don't have all the availability as you do in Europe. With over 30 years experience with these cars, my advice is to not substitute much of anything.

Removal of a tight sphere can be accomplished with a chain wrench. This is a very cheap tool available almost anywhere. I have two of them. One has a long handle, the other uses a 1/2" ratchet wrench. Works well in those tight TurboR spots.

Gas Springs, the rear suspension spheres are only calibrated to the cars, do not substitute anything unless you want to ruin the ride. They are not the damper, the shock tube is. Also, replace the bypass tube on the lower end of the shock, otherwise you're going to have leaks eventually.

If you want to save money, get your green fluid from Nissan. It's actually a better product, 1/4 the price, and larger quantity. The Infinity A cars used this fluid and it's fabulous.

You shouldn't have to rebuild the valve assembly. But you should inspect the pumps, as the o-rings are notorious for leakage.

Good luck.
 

·
Registered
Joined
·
79 Posts
Is there a more defininite specification other than "green fluid from Nissan"?
Where does Nissan use it in their cars and what is Nissan's name for it?
Leho
 

·
Registered
Joined
·
9 Posts
The fluid

You want active suspension fluid for an Infinity Q45A. They have it, they know what it is, and it's a better quality mineral oil. You'll like the savings.
MB
 

·
Registered
Joined
·
31 Posts
Re: fluid

MasterBentley said:
the fluid mixes without any problems.
Ok, no offense, but you people are really scaring me about these cars now. I mean, a McPhearson strut I am all over, and provided one is careful with the spring compressor, its a couple of bangs with an impact wrench either way. Ok, not quite, but you get my point. I can deal

But weeping spheres, that sound like they are intertwined with the braking system?
 

·
Registered
Joined
·
78 Posts
Hydraulic accumulators.

Roughly how the system works.

The reservoirs feed the brake pumps, (these are driven by the camshaft). The brake pumps feed high pressure to the valve bodies. These will regulate the pressure of the system and maintain the correct pressure (between 2000 and 2500 psi). On the valve bodies you have accumulator spheres. These have a diaphragm with one side connected to the hydraulic system and the other side charged with pressurised gas. The pressure should be around 800 - 1000 psi.

If you have left the car for some time and the system has de-pressurised, the only brakes you will have is the pressure in the accumulators (it takes a while for the pumps to achieve the correct pressure). The gas in the spheres also act as a reserve. You cannot compress a fluid so without the gas in the spheres you would only get one pump from the brakes.

I do not know the pressure in the Citroen cars, but I do know that there are various different pressures available in these green spheres. The ones on the rear suspension are much lower pressure than on the brakes. I would be careful about fitting self sourced ones unless you do all the necessary research. The alternative spheres are readily available. you can visit the Introcar website for prices if you want. CD6000 is the Rolls/Bentley part number.

The correct fluid is the most important thing. Be very careful not to use the wrong fluid. The rubber seals on these cars are designed for LHM mineral oil. Using the wrong fluid can cause all the rubber seals in the system to swell and perish and you will be looking at a huge bill to correct it.

I hope some of this information helps someone some were.

Thanks Matt.
 

·
Registered
Joined
·
1,553 Posts
Hi to you all
I have been reading your posts and it has got me wondering why you are trying to run a RR or Bentley in a shoestring
I can understand why the Yanks do it as they don’t have the ability to get cheap genuine parts
Brakes are there to stop you and keep you out of Hospital
Citron developed the system and RR modified it to suite there cars
You have people like Mat that will get you discounts on parts and also give advice
Why bother trying to get a free Holladay in Hospital
 

·
Registered
Joined
·
31 Posts
bentleyman22 said:
Hi to you all
I have been reading your posts and it has got me wondering why you are trying to run a RR or Bentley in a shoestring
I can understand why the Yanks do it as they don’t have the ability to get cheap genuine parts
Brakes are there to stop you and keep you out of Hospital
Citron developed the system and RR modified it to suite there cars
You have people like Mat that will get you discounts on parts and also give advice
Why bother trying to get a free Holladay in Hospital
Why do you think us Yanks want to try and run our cars on shoe string budgets? I have always taken care of my cars, and done so with either OEM or original parts. I have a supplier that sells me original parts for less than some aftermarket junk.

One of the reasons I am trying to find out so much infomration before plunging on an Arnage is because I do care for my cars, and the cost of ownership matters. Do I play tricks, like try and source a Bosch part under the Bosch number instead of the marque part number so I can pay 25% less? Sure. But I darn well won't do something that leads to early failure, especially on critical parts.

Too right I don' t want a Holiday in hospital.
 

·
Registered
Joined
·
1,553 Posts
You’re a bit touchy try reading what I said
I have been bring cars from the us for 20 years and spend most of my time removing (after market parts) from Aston’s to Bentleys
As you’re so concerned there must be a dealer near you so have peace of mind and just take it to them and be happy


By the way my Bentley runs very smoothly and my Jag
:lol: 8)
 

·
Registered
Joined
·
31 Posts
I am just saddened, not really touchy. I try and take very good care of my cars.

No, there isn't a Bentley dealer near me, its about 2 hours away at best. The car has to be repairable at times by someone who's very competent with European cars. I am a control freak , so there are some things I plan to do myself. I have spent some time talking with the RR Foundation director who has an Arnage and he has been very helpful, and says yes, mere mortals can work on these cars.

Is the Jag still British after ll those years with Ford ? :roll:

Glad to know that the Bentley doesn't suffer all those battles I remember with choke fiddling, etc. I thought I did read car and driver say the Arnage had a tendency to stall on cold starts. I thought " How original."
 
1 - 20 of 25 Posts
Top