Re: Vacuum Pump and Whatnot...
Tesla List wrote:
> Original Poster: "Michael Novak" <Acmnovak-at-execpc-dot-com>
> My vacuum pump was taken from an old air conditioner and no longer can
> reach a very low pressure as it once could. I am led to believe that it
> requires an oil change. However, I can't get open the oil spout or
> might have some kind of locking compound on the threads of the bolt which
> in the dipstick. Would it be okay to put oil directly into the vacuum
> through the input? I thought I would consult the more experienced before
> making such a decision.
The refrigeration compressors here in Finland (at least the
one I have seen opened - with disk grinder) did have _output_
directly from oil space and input directly to piston. So, one adds
and drains oil via output.
The same (output connected to oil space) applies for most pumps,
see http://www.hut.fi/~kukkonen/es50/es50_overhaul.html for details
of Edwards single stage rotary vane pump oil flow diagram. It has
a separate oil port, but it is connected to same oil tank space
as the output.
So, I'd _guess_ that you first have to drain the old oil from
output (by gravity, ie. turn pump upsidedown and let oil flow
from output hole) and then refill with new oil by pouring it
to output hole.
If you were to pour new oil to input, you'd have to rotate the
pump mechanism as the oil would have to go through the pumping
Another thing to notice is that not all oils are compatible,
so first get some of the old oil and mix it with some of your
new oil and see what happens.. If they just mix, great, if they
foam, turn into solid :) or something, you'll have to clean the
pump of old oil (disassemble it) before adding new oil, or more
realistically get some other new oil. Most propably there is no
problem, but it is easy enough to check.