Just recently bought a hfs 12cfm pump that claims it pulls 15 micron, when I bought it originally it pulled 6 micron after getting it warmed up for an hour. After getting it moved onto the work bench I decided to do another test before hooking it up to my 1l spd and now it wont break 50 micron, once warmed up it shoots down to 50 micron then gradually goes upto 110 when its hooked directly to the pump. Does anyone know why it goes down to 50 then after about 5 seconds starts to drop? Could my bullseye gauge be fucked up or is the pump just a peice of crap?
When a pump has dirty oil in it or needs a good cleaning it will pull down to say 10microns right off the bat, but as it warms up the stuff that was trapped in the oil starts vaporizing and so your reading starts to go up and in my experience it will go up around a hundred microns before it levels out. It probably needs a few good flushes and a few oil changes to get it back to 100%
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The pump was brand new out of the box, havent pulled vacuum on anything besides fresh air! Iâll try running it for a couple hours or so and replace the oil with black gold and see if it gets any better, came with some cheaper looking oil thatâs in it currently, like I said it pulled 6 micron on friday when I got it but now isnt getting anywhere near that.
Not too sure on this one, I would get some INLAND 19 pump oil though. Black gold is cheap but it isnât really good for high vacuum. USA labs sells a gallon of inland19 for ~$50 I believe
Think I figured it out! Might have been sent a used pump instead of a new one, changed the oil and the old oil smells like weed and is dark⌠once I replaced the oil it fired right down to 8micron and Is holding
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Vacuum pumps are supposed to go lower as they warm up.
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@Anthony420 did they sell it as ânewâ or ârebuiltâ?
rebuilding without cleaning would be consistent with working until you got it nice and warm, then let it sit.
If it was sold as new, you should try and get at least some of your money back, if it was sold as a rebuild, Iâd still let them know that they screwed upâŚ
Iâd keep @Bearschoice710âs advice in mind, consider flushing, especially if you notice a similar drop-off in the first couple of usesâŚand oil quality definitely affects ultimate vac.
@spdking absolutely! they also require relatively clean oil to behave that way 
I would have expected you to call out the oil quality.
whatâs your take on the hvac standard âblack goldâ, verses any old â19â, vs âonly Edwardsâ (or whatever OEM is selling)?
when youâre abusing a cheap rotary vane pump and should ideally change oil daily (say rotovap duty), can you get away with using dairyland or mineral oil?
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Was sold as new, Iâm gonna try it out for the next couple of weeks and change the oil more times then usual, if it sucks it will be sent back. any suggestions for a sub $2k vacuum pump?
You can buy a used Alcatel 2021i off eBay for ~$400. It is certainly a gamble. I have had good luck in the past and the pumps work great (1micron), although Iâll probably buy new or rebuilt in the future so I donât have to flush the shit out if it
All good advise here.
Black Gold is not great, so thats the first thing to address. Also, a clean pump will pull down further after it has warmed up, a dirty pump will do just the opposite. As for the quality of those HFS pumps, it is not great, but it is an âeconomyâ pump, so you get what you pay for. They are rated @ 15 microns, which is being generous.
Of course you want to get as closet to 1 micron as you can, but the difference between 15 and 1 is huge and the differnce in the quality of pump needed to get thos e last 14 microns out is huge, too.
As always, feel free to call us at AVAC, we will be glad to help. And for the latest info and best deals, give us a follow at Instagram.
Its not under $2k, but it is absolutely a new pump. And if it gets filled will Volatiles and fails, you can replace the pump module with a new one.
Enter BroxTek as the discount code
Get a rebuilt brand name pump. These are all garbage imports. A brand name pump can be rebuilt numerous times back to factor. Import shit pumps basically die and go out of spec after one rebuild.
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I have changed the oil in my Edwards RV8 and seem to be having a similar problem it pulls to 120mTorr then as it warms fluctuates from 400mTorr-1Torr how would you suggest to flush the pump or do any maintenance. I currently have just been replacing the oil filter attached on top as well as changing the oil but is âflushingâ the act of letting clean oil run through and out a few times before putting more new oil in? Sorry I am rather new with pumps and mechanics. But will try to use Inland19 or what is the best oil for pumps in your opinion as im not sure how quality my oil is as well as flushing the system. Any other suggestions?
Try flushing fluid sump when its hot and you can always do the breaking dabs acetone clean. Works great for me
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I am an idiot and after calling Edwards Tech Support have realized that people here before me have been filling it with the wrong oil and is too thin. So believe if I change the o-rings and get the correct oil it will seal. The tech said that this oil were using is too thin so gets too hot and does not seal the system efficiently. Long story short have realized to double check everything and call the manufacturer of all the equipment as sometimes you are handed the wrong instructions haha!
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This is what ive been using for awhile now, ive used 19 i just like this a lil better. I do oil changes after every 2nd 2nd pass so i go through a decent amount of oil. Change my roughing pump once it wont go below 100-125 micron
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Wow that is a lot of oil changes we try to change it once a week only running about a pass a day so probably pretty close sometimes let it go two weeks but wonder what is suggested time frame. I mostly have just gone on if my vacuum pressure is good and no bad smelling oil let it fly.