Xantia Accumulator Sphere

Clive, Actually gas diffusion does happen through steel as steel is a molecular structure, The time taken to notice any loss at all would be years though, (luck for the divers indeed)

Regards Slim

Hydraulic system flushed, filters washed, LHM replaced. =A325 ?????

If it sounds to good to be true, It normally is too good to be true!!

To flush the system First drain the fluid, remove the reservoir and wash, including filters (using parrafin) Fill with Hydraflush, then excercise the system for at least 20 mins. up, down, steering etc. Remove the wheels and bleed through each brake caliper. Drain the fluid again,. Remove the reservoir, wash again and wash the filters. Re-fill with QUALITY, ie Castrol or Total LHM Bleed through each caliper untill clean LHM is seen at each bleed nipple.

All this will take about 2-- 2.5 hours + =A315 ish for the flushing fluid and =A325 for LHM.

Sorry to piss on yer fireworks but thats just my opinion.

Regards. Slim.

Why have you given me a link to a page explaining how gas diffusion is the rate two gases mix?

How fast do you think nitrogen diffuses through steel? You earlier implied it would be sufficiently fast to explain spheres going flat. This is of course at normal temperatures, ie say 40C max. Do you think any would have escaped the spheres by the time the earth stops existing?

(What is a molecular structure in this context?)

cheers, clive

Sorry But I already said that I am not to good at explaining tech bits!!

Gas migating through steel does happen albeit very very slowly, infact the rate is insuggnificant.

The sphere going down is gas migrating through rubber, as in a sphere the diaphragm sits about halfway up the sphere during normal use.

The rate of a sphere loosing its pressure is determined by use and heat, the front spheres and accumulator will loose pressure at the rate of about 10 bar per year, and the rears by about 5 bar per year. (under bonnet heat accounting for the greater loss)

The way I read it molecular structure is the fact that everything is made from tiny molecules!!!!!!!!!

Yeah ok sorry again wrong link??? But if you google Graham's Law you can find out all sorts of very booring info if you feel realy bored.

Regards. Slim.

At ambient temperature how much does it happen?

Agreed.

Well, y'see there's a bit of your problem. Metals aren't made from tiny molecules. Everything is made from atoms, yes, but the structure varies quite a lot. You've got conventional covalent molecular bonds in the little molecules like notrogen and water, going to bigger ones like octane, proteins, DNA, polythene, etc. Minerals can use the same bonds - eg diamond, quartz, and that can lead to some quite big lattices. Then you've got the ionic bonds - eg as in salt - that's not really a molecular structure at all. Then you've got weaker bonds holding the molecules together - eg hydrogen bonding in water and most molecules involved in life. Then you've got metals, which are something else altogether. Great lattices of metal atoms, with electrons whizzing about all over the place, all shared (hence electrical and thermal conductivity). You can squeeze some smaller atoms into the lattice - eg carbon for steel, and nitrogen, but that's as atoms - the Nitrogen doesn't exist as the gas molecule. Metals also tend to have a crystal structure - look eg at the surface of galvanized steel - where different lumps of these great lattices meet.

cheers, clive

You can squeeze some smaller atoms into the lattice.

Or if we could split one!! now theres another thread!

Clive, you obviously know tor molecules and atoms.

Where you my physics teacher? cos I diddnt listen very well did I, D-

Regards. Slim.

Gasses do indeed diffuse through metals. The rate depends on the metal, the thickness, porosity, temperature, gas, but is generally orders of magnitude below that through plastics or rubbers. And it's not inherent that the spheres have to go down. It could use a metal bellows inside, for example.

The message from Ian Stirling contains these words:

The reason hydrolastic used to go down (apart from losing fluid) was mostly 'cos the nylon threads that reinforced the rubber crept under load. They were replaced with terylene which didn't. I know this 'cos it was one of the first reserach things my brother did for Dunlop when he joined them after leaving uni many moons ago.

Go on, how many orders of magnitude for nitrogen through accumulator-thickness steel at room temperature? Will any make it out before the end of the solar system? (assuming it doesn't rust :-) )

cheers, clive

Is there a postcode at all for these guys as save me buggering about under the bonnet and all in the future :o)

Ta, Will

Will Morrow ( snipped-for-privacy@chavman.chav) gurgled happily, sounding much like they were saying :

Do you need your nose blowing for you as well?

Achoo ;o)

Thank you :o)