I accidentally turned off my vacuum casting machine before the pressure released all the way and it looks like I got some oil sucked up into the pump. What do I do?
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You should contact the maker of the vacuum pump to be sure how to deal with that since they are not inexpensive devices and you don’t want to ruin it.
On mine the air that gets vacuumed out is exhausted through a port, and that exhaust can include a little oil. In your case it might be a lot of oil which could spray out and make a mess, so be prepared for that when you clear the problem or use it the next time.
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I’m really curious to hear the answer to this question as I’ve always wondered why you’re supposed to release the pressure from a vacuum pump before turning it off. I alway do release the pressure before turning off a vacuum pump, but none of my teachers ever explained why. I was just taught that it’s better for the pump.
Jeff, this is from duck.ai (duckduckgo browser that queries Microsoft Bing):
Search Assist
You should release the pressure on a vacuum pump before turning it off to prevent oil backflow into the vacuum chamber, which can contaminate the system and damage the pump. Keeping the pump running until pressure equalizes helps maintain system integrity and avoids potential leaks or performance issues.
Auto-generated based on listed sources. May contain inaccuracies.
The two included links are supposed to be where duck.ai (bing ai) got the information and you can click on them to read the source.
How to clean a contaminated pump is another matter so I tried: “how do you clean a vacuum pump that has had oil sucked into the vacuum chamber” and got some youtube hits, the following being the only one that was a direct answer. I dunno about the cactus juice…
Youtubes can be a great help, and maybe there are others that would be useful.
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Thanks Neil! Like I said, I always have released the pressure before turning it off, because that’s how I was taught, but never knew why. Thanks again!
Thanks! This is very helpful! Yeah the oil looks cloudy through the little sight glass on the side.. so I definitely got some investment contaminating the oil. I’m going to start by draining the oil and getting new oil into the machine. The problem was when I released the pressure.. for some reason the pressure wouldn’t come down.. I panicked and flipped the switch to off (not my smartest moment). I definitely won’t be doing that again 
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This is how we learn. I like to say that I make jewelry and have been screwing up for 53+ years. Neil’s suggestion that you talk to the manufacturer is a good idea if they will pick up the phone. Good luck…Rob
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