Hydraulic pump (& system) - General questions

[David]

Just some curious questions, so here goes;

When a pump is off a car in storage, can it rust/ corrode internally causing it to lose its power & cause it to go noisy?

What actually causes them to wear? I know mileage will be a great contributing factor, but is there anything that would greatly speed this up?

Would air in the hydraulic system give the impression of a weak & noisy pump, including heavy steering & slow rising suspension?

How long does it take to purge out the system, if raising & lowering the suspension was employed?

Is it possible to damage pumps if they are run low on oil or are air locked?

How many different types of pump are made for the BX? I know petrol & diesel are different, but are there different types of pump fitted to each?

[ken newbold]

Yes, no, yes, not long, no and dunno.

[Dragon Man]

the last one is an interesting question.. i have wondered if a hydro electric system could be made to do all hydraulics. i know its a common thing on most cars to have an electric motor drive a hydraulic pump for the power steering. if ever i was to go crazy with a BX and install a later PSA common rail diesel engine, it would be the way i would do it.