What’s wrong with my vacuum pump?

I have a five-gallon vacuum chamber that I use for storing drugs and nutritional supplements. It’s been working just fine up until recently. Then one morning I opened it and there were several tablespoons of the pump’s machine oil on the bottom of the canister. Blown gasket? Try to have it fixed, or just toss it and buy another one? (They’re not horrendously expensive.) Here’s the pump with the one-gallon chamber that came with it. The five-gallon chamber I purchased separately. Here’s the pump by itself. I just now noticed that there is a little bit of oil on the pump, underneath the oil-level view port. Can’t find the stupid warranty card, of course. So junk or fix?

It doesn’t suck? :smiley:

In keeping with the longstanding rule to not joke in a GQ response before a legitimate attempt at an answer, I’ll say your guess about blown seals in the pump seems likely to me. Dunno 'bout repair versus toss, though. Depends on the complexity, cost, and parts availability of whatever failed in the pump. YMMV.

ETA: for approx. $100, I’d do a wholesale replacement on the pump. The time required to break down, replace, re-assemble, lube, and check out the old pump makes it so that DIY is cost-effective only if your time has no value.

Also, do you expect the pump to hold the static vacuum all the time? I would think you’d pull the chamber down to the desired vacuum and then close all the valves to give the pump a break.

That’s a nice pump, sir.

I assume it is a rotary vane pump? Is that right?
You said you had excess oil, but are you still getting a vacuum?
Would you be comfortable taking the head off?

We use rotary vane pumps every day here at work and it’s much cheaper to fix them. Hell, that electric motor’s expensive, ha! Usually, there is an off-the-shelf rebuild kit for these babies, but i’m not familiar with your specific unit. I’ll try to help if I can, though.

I was planning on cleaning it up tonight and seeing if it still works. I’ll give you an answer to that soon. But I detached the hose and stuck my finger on the end to see if it’s still drawing air, and it is. Tonight I’ll see if it can still pull a good vacuum.

It is? It got good reviews on amazon, but originally I was a little afraid to buy it because it was only a few dollars more than the cheap Chinese ones. Glad to be assured that it is actually a quality unit. If it’s fixable, I’m pretty sure I can handle the job myself if I can source the parts. I’ll get back to you on the other questions too; thanks for your help.

May I ask why you store your drugs and supplements in a vacuum chamber? I assume it’s to prevent oxidation or something like that. But flooding the chamber with nitrogen would seem to be more effective.

Also, by keeping these things in a vacuum, you’re ensuring that any volatile compounds in your drugs and supplements are boiling off and being sucked out by the vaccum pump.

So why a vacuum?

Can you explain your operation?
How far of a vacumn you are pulling and how long are you running the pump?

Sorry I took so long to respond. I just now got around to disassembling the whole thing, cleaning it, and putting it back together. It seems to be working fine for the moment. After I made the OP I later remembered that one night I had inadvertently left the valve on the chamber in the open position after pulling almost a full vacuum. Since this was the first time I had ever done that, and they both happened around or at the same time, that’s the most likely explanation. I use the chamber only for very hydroscopic compounds which I buy in bulk powdered form. The pump is a little on the small side, so it has trouble going to 30. I usually take it to about 27 and shut it off immediately.