Automotive Air Conditioning Information Forum

Before asking tried searching "pump oil" in topic title and got rejected for words too common.

https://www.autoacforum.com/search.php? ... mit=Search

What viscosity or other pump oil characteristics would be a good place to start on a no-name typical vacuum pump? No manual either.

Thx.

Cusser wrote: ↑Fri Oct 27, 2023 11:32 am https://www.ackits.com/12-oz-vacuum-pum ... pump%20oil

What is the benefit / objective of this oil which is at viscosity of ISP 150?

ISO 150 is very much at the top of the viscosity range of what's available for vacuum pumps.

Most pumps of similar physical appearance say 46 in the manuals I've been able to find. Other common viscosity is 68.

Curious what benefits come from such a higher viscosity number.

Thanks,

Ask whoever you bought the pump from for a Manual, and the correct oil.

bohica2xo wrote: ↑Fri Oct 27, 2023 6:30 pm Ask whoever you bought the pump from for a Manual, and the correct oil.

I wish I could. It was gifted to me. None of that possible. I tried to make clear the lack of info in the original post. Hence the question here....I really do try to figure things out before posting.

At my 5,500 ft it pulled 3600microns with the dirty oil it came with. Likely put away wet with water in the oil since the sight glass reflector is rusted. I have some 46 oil I'll flush/run/flush with but I'd like to optimize the approach with the best oil and advice if possible.

Its a project, likely makes sense to not even bother with it but I'm curious what it could turn into ....Some people knit, some people fix stuff.

... Interesting thing I read on a vacuum bump board - purportedly by a name brand service tech to a pump customer - to really clean a cruddy pump, one you may throw out anyway, empty the oil, put a funnel in the intake (not the fill post, the intake where the gauge hose goes), turn it on and pour oil into the funnel. It'll flush the crud from the internal mechanism and shoot the crud out the drain hole at like 100mph....That'll be fun to try.

oh, and how many microns would be decent performance at 5,500 ft?

Some sources say reduced pump performance at altitude. Some sources say altitude doesn't matter since with microns you are reading absolute not gauge pressure.

...sorry about the topic drift, maybe I'll change to "get an old vacuum pump vacuuming" or something if it drifts in that direction.