Vacuum pump not pulling good suction

[marinechiller]

I suspect this is a simple question for most of you, but why would a vacuum pump only pull down to 20" if:
a)oil is good
b)no leaks

It is a used vacuum pump I inherited that was supposed to be working.

Thanks,
Marinechiller

[lowcool]

it is working just not to well.its time for a rebuild

[sedgy]

put your torr gaugue streight onto your vac pump. what is the reading?

[Brian_UK]

Needs a new pump pack.

[marinechiller]

Hi Guys,

Thanks for the help. I put the gauge straight on and was getting -20". Then I absent-mindedly noticed that the handle wasn't straight and straightened it out (it bolts right into the pump end). The pump immediately got a deeper sound and started pulling more vacuum. Within 5 minutes it hit -29"

:o

Thanks,
Marine Chiller

[Grizzly]

Interesting post marine chiller!
As they say it's amazing how well things can perform.
When they can breathe!

I am assuming that the exhaust port of the pump is through the handle.
Sedgy is correct in that adding your
Torr gauge to the line.
Preferably just at the point where you are going to attach it to the system.
Not only proves your vacuum pump but also your gauges / hoses etc.
Cheers Grizzly