Hi folks. Got myself a new vac pump and hooked it up to my oven for the first time and it doesn’t seem to pull a full vacuum. I accidentally started filling it with oil through the exhaust port before realizing it was not the oil port. Looks as if they both fill the same resivour but might I have done damage by putting oil in the wrong place? Only getting to -27hg. Also the manual says to remove the exhaust plug but doesn’t actually say what that is? Thanks for the help
where are you located? 27"Hg is awesome in Denver…
pics? or at least brand?
what makes you believe the gauge?
I see lying gauges all the time.
do you have anything other than the gauge attached when you generate that number?
no, pouring oil in the wrong hole should generally not hurt a rotatory vane pump. as you noted, oil should end up in same reservoir
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isnt the exhaust plug the cap that screws into the exhaust port? They just want it out when you run it so the exhaust has a place to go.
Not sure what kind of pump you have but I have a cheaper robinair pump for my vac chamber and I was only getting to -27hg for the first few uses. After changing the oil a few times it gets to -29.5 no problem. I feel the pumps may need a bit of a break in period. I have no science to back that up though so take it with a grain of salt
Did you warm your pump up for a half hour or before checking vacuum?
In the manual it says to remove the exhaust plug from the exhaust fitting and discard. So I assumed it was something other than the exhaust cap that screws in. Doesn’t seem like that should be thrown away. Suppose maybe it does need a warm up period? I’ll try running it for a longer time and see if it pulls any deeper. I’m in CA and have pulled -29hg on a different oven/pump. The oven and pump are both from Xtractor Depot
On a dual vane pump pouring oil into the exhaust port does no harm except it will blow some oil out your exhaust hose. To clean my EM-28 in fact I overfill the oil until it cannot take anymore through the fill port. Then with exhaust hose ported to a catch point I run the pump with blank off valve full open.
it makes one hell of a mist and pukes out the half quart or so of overfill but boy does it do a great job at cleaning out the pump without additives. An overfilled dual vane pump is pretty quiet too but mostly this technique returns the pump to new specs by flushing all that oil through and out the port. The exhaust port is simply opened onto the oil case just like the fill plug. The exhaust ports out into the oil resevoir and through the oil then out the exhaust port.
The downside is loss of half a quart for flushing and the mess to clean of the oil coming out of the exhaust hose but the thorough flush you get far outweighs the disadvantages. Note that I could not find any reference to damaging the pump from overfilling in the Edwards literature except for only loss of oil by doing it until the overfill is corrected. So even if you overfilled the tank the worst to expect is the pump will blow out oil until the excess has been jetisonned. I love dual vane pumps because they are relatively cheap and their simplicity of design makes them generally pretty rugged.
Good luck and hopefully your error will help flush the pump better than it has been for a long time lol.
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