Comptometer / adding machine oil?

[Tony Duell]

> 
> I know it's not quite the same thing but on the small mechanical parts 
> of hydraulic systems I work on, I find that some of them are almost 
> impossible to get sorted out unless you dunk them in a bucket of petrol 
> for a while and flush the worst of the crap out before you even *start* 
> to take them to bits.

Completely OT, but when you dismantle a Citroen hydraulic system, you do 
clean round the unions (unleaded petrol is the recomended cleaner in the 
factory workshop manual..) before undoing things, to prevent said dirt 
ending up inside the sytem.

However, any antique clock repairer will tell you not to clean a clock 
before dismantling and inspecting it. Often marks in the dirt will give 
information as to the size of a missing part, of what's been rubbing 
where it shouldn't and so on.

In the case of computers, I think the latter applies. They're unlikely to 
be as dirty as the underside of a car :-). And as with clocks, a mark in 
the dirt may show where a linkage has been scraping on the chassis or 
something.

-tony