Replacing Spheres

[jackyboy]

Has anyone got a simple instruction procedure for replacing the rear spheres on my 2.5td. It needs to be idiot proof. I have seen instructions offered on Ebay 'The easy way to change spheres' and wondered if anyone had seen it

[dean]

Hi jackboy

The rear spheres need to be 'cracked off' while under pressure and with the weight of the car is on the wheels, if they are not the rear struts can move and damage their feed pipes. Put the car to its highest setting and put axle stands under the rear cross member, just in case the car decides it wants to sit on you, or better still put the car on ramps. Then all you have to do is take your weapon of choice (oil filter wrench/sphere removal tool) and get the 2 strut spheres to undo (half a turn MAX at this stage). Now start the car and put it in the lowest suspension setting, with the axle stands under the cross member the back end will settle down on the stands (no jacking necessary ) now leave the car running like this until it has settled, then turn it off. open the bonnet and on the pressure regulator (sphere between engine and radiator) there is a 12mm bolt, undo it (MAX of 2 turns) until you hear a hiss, this is the pressure release or bleed screw, If you undo it too far the ball that it retains will fall out and it is quite small and easy to loose, i should know .
Now you can undo your spheres by hand the rest of the way and fit the new ones, dont forget to lube the new seal with lhm and fit it to the strut not the sphere, and only do the new spheres up HAND TIGHT ONLY, if you dont you will not get them off again.
To get to the centre sphere i took off the last 2 sections of exhaust removed the heat shield that is above them and it is straight forward from there, you could remove the spare wheel carrier to make access easyer but its not necassary.
Once you are all done and it is back together start the engine and let it run for a few minutes with the bleed valve still open, then close the bleed valve and move the suspension from the the lowest to the highest setting and back a few times to get any air out of the suspension circuit also check to see if you have any leaks (you wont, but check anyway)
Now all you have to do is bleed the brakes, which is easy on a cit because you can do it on your own , rest a brick on the brake pedal with the engine running, if you have alloys like me you can reach through the wheel putting a piece of clear tube on each nipple and let it run until there is air free lhm, if you have standard wheels sorry, you will have to remove them at the back, you can reach around the front wheels but it is a bit of a fiddle and and a lot of people take the fronts off as well. Finally put the car back to the highest setting and check the lhm level. Really is an easy job, and if you get stuck someone will be here to help.

P.S when i said undo the two strut spheres it sounded like they just undo, do not be fooled, i will not be held responsible for your foul language and grazed knuckles

Dean

This post has been edited by dean on February 18, 2008 06:43 pm

[noz]

Hi jackyboy,

Just a couple of points to add to Deans excellent description:

On my saloon I don't drop the exhaust to reach the centre sphere. I drop the spare wheel carrier which is easier. I then uncouple the 3 rubber hangers and let the whole exhaust fall about 300mm. Thats just enough to give you acccess to the sphere but not enough to cause the exhaust any distress. When in the lowered position its best to provide a very secure way of stopping it falling any further. Otherwise you're likely to bend the mid-pipe or burst a connection somewhere.

When bleeding the back brakes its necessary to have the suspension on high setting because the back brakes are fedd off the suspension pressure. If you've got the body suspended or even on low setting there's insufficient pressure to push the fluid out of the bleed nipple.

I have a Pleiades tool for removing spheres. To give you an idea I took my rear spheres off at the weekend after approx 2 years since the last time they were off. With the suspension on high I had to resort to a hammer on the handle of the tool to get them to break free. Watch the rotation of the strut like a hawk. If it turns, all of the force from the hammer blows will be absorbed by the hydraulic pipe with dire consequences. I also add a little grease to the seat of the sphere where it comes into contact with the strut. Once assembled onto the strut I also fill the gap between sphere and strut with waxoyl or underseal or anything really to keep the water out.

Jope that doesn't put you off. Please let us know how you got on.

Cheers

noz

[techmanagain]

I picked out the "Top Tip" among all the other useful stuff, and that was -" tighten the sphere only by hand, otherwise you'll never get it off again."
I know there is an almost irrestible urge to get a tool on it "just to make sure it won't loosen" - but resist it. The internal pressure will be quite sufficient to prevent any loosening and you'll bless the hand-tight tip when next you have to change them!
so, "Top Tip = Hand Tight"

[demag]

That's a handy tip noz ref the centre sphere. I have to do mine soon as the back end is firm. Is there much room to work with the exhaust hanging like that? I will be using one of the ebay removal tools. I used it for the front centre and it was ok. I asked the indie to do it when he did the mot but he still insists the centre sphere is antisink!!! He's obviously looking at the wrong part of the subframe! There is still enough movement on the rear suspension for the mot but it's like being in sport mode.

[DerekW]

The only thing I would add to the excellent tips already given is that it may be worthwhile wire brushing around the sphere joint and then spraying with penetrating oil (not WD40) before you try to undo them.

Derek

[jackyboy]

Thanks everyone for your help on that. The main difficulty I see is getting access to the pressure reg on my 2.5 when the car is sat low. The only way I got access before was by putting the front on ramps and getting access from underneath

[dean]

Forgot about the car in the high position for bleeding the brakes its easyer to jack up as well.

Cant help with getting to the regulator though, never worked on a 2.5, if the bleed screw is impossible to reach from above it will be easyer to put the whole car on stands if you have two sets.

Dean

[rowanmoor]

You can get to the bleed screw from above 'fairly easily' on the 2.5

You need to undo the 2 bolts holding the bracket for the fuel filter onto the - er is it battery box, whatever it is attached to anyway. Then you can move this out of the way and rest it on something (I have bypassed the fuel heater - you may have less pipe to play with if you haven't). Then you can reach down to get to the bleed screw from above. Watch out for your arm on the radiator if it is hot though.

You are doing it blind so have a good look and feel where everything is before you reach down with the spanner.

[noz]

Hi jackyboy,

Undoing the regulator bleed screw is really just belts and braces. In truth its not absolutely necessary. It just constitutes good practice. When you lower the height control lever to the lowest position the connecting rods push and pull on the two height corrector control spindles accordingly. The movement on the spindle valves allows the pressure stored in the wheel circuits to spill back to the reservoir and the same valves prevent any pressure available from the regulator from reaching the wheel circuits. Once the wheel circuits are empty of fluid no more fluid can get through the height correctors no matter if the regulator circuit is depressurised or not. The only exception to this is if you have leaky height correctors.

As long as you don't move the height control lever whilst working on the spheres then there's no absolute reason for depressurising the regulator circuit. As I say, normally everyone does it because its just good practice. If its a real pain to get to then I'd leave it alone.

cheers

noz

[aengus-xmv6]

as Noz says, you don't really need to fiddle with the regulator.
Believe the procedure is:

engine running
steering dead ahead
doors closed
set suspension to low
leave engine running for 1 min - do not move steering etc
engine off

car should now be ok to work on the spheres.

That's typically the way I've done it before.

regards
Dave

[Assich]

I seem to remeber that the threads on the spheres are inside the seal and so there is no way that WD40 is going to get to them. I loaded this post a while ago re a useful tool for removing the spheres.

Sphere Removal Tool

[wirdy]

The spheres also corrode around the machined flange above the threads, causing difficulty in removal - been there, got the T-shirt! this is normally where the WD40 helps

[Peter.N.]

I have never found that the centre spheres have completely depressurised, so prepare for some spillage. If all else fails a hammer and chisel into the welded seam around the middle in an anti clockwise diretion will loosen the spheres.

Peter.N.

This post has been edited by Peter.N. on February 20, 2008 10:57 am

[DerekW]

I never suggested that the threads would corrode. As Wirdy wrote, it's the exposed flange that is susceptible to corrosion.

I would NOT use WD40, it's a water displacing fluid (WD - geddit?) not a penetrating oil. Use the correct stuff and you will get better penetration. That sounds like one of those funny emails I keep getting!

Derek