A Vacuum Pump Oil Change Should Be Done Periodically
If the vacuum pump on your Harvest Right Home Freeze Dryer uses oil, a periodic vacuum pump oil change is necessary to keep the pump running smoothly and quietly.
The vacuum pumps that Harvest Right has employed for their freeze dryers have evolved over time – from the first, outdated JB Industries Eliminator Vacuum Pump – to the Harvest Right Standard and Premier Vacuum Pumps – as well as the Harvest Right Oil Free Vacuum Pump.
The job of each of these pumps was to create an extra deep vacuum of less than 500 mTorrs (millitorrs).
JB Industries Eliminator (6 CFM) Vacuum Pump
Back in the days when I first received my brand new Harvest Right Freeze Dryer – many moons ago – the vacuum pump that came with it was a JB Industries Eliminator (6 CFM – “cubic feet per minute”). This was JB Industries’ economy model vacuum pump – which was designed more for an Air Conditioner Technician – and not so much for supporting the stringent requirements of a freeze dryer that required a very deep vacuum.
The oil needed to be flushed out of the pump after each and every use. I actually did a double – or triple – flushing each time – which used up a lot of oil.
Additionally, after every 4 or 5 freeze dryer runs, the oil level window would start to get dirty – which meant taking it apart – removing the cover – and thoroughly cleaning the interior. This was a very messy, dirty, scummy job. I would rather snake out a clogged water drain pipe than clean out the vacuum pump. That’s just how messy it got.
The pump was prone to oil leaks – as well as spraying oil all over the place through the overflow “oil mist” tube that doubled as a pump handle. I covered the “oil mist tube” with an old sock – using a tie wrap – which minimized the chance of spraying oil all over the house.
Plus, a pair of pliers was usually needed to open the oil drain.
Lastly, this pump retailed at around $350 to $400 – even though it could barely maintain the required vacuum pressure (less than 500 mTorrs) consistently.
All in all – this was a poor choice. I limped along with this vacuum pump for a couple of years – going through a couple of them – until Harvest Right finally came up with their own vacuum pump.
Enter The Harvest Right 7 CFM Standard Vacuum Pump
What a step forward! This vacuum pump – selling for around $295 – was Harvest Right’s answer to many problems created by the Eliminator pump from JB Industries.
With this 3/4 horsepower vacuum pump, oil did not need to be changed out completely – after every freeze dryer use. I just had to drain a little out to remove the water and particulates that gathered beneath the oil. The recommendation is to completely change the oil every 4 to 5 batches.
There is an “oil mist filter” on top of the cover that allows a minimal amount of oil to escape into the house – but, I used the same trick that I did with the JB Industries Eliminator pump – and, covered the filter with a sock – held in place with a twist tie.
That being said, I still preferred doing a complete oil flush and change after each use. It only took about 10 minutes and I always had a pump full of fresh, filtered oil ready for the next freeze drying run.
The oil drain was easily open and closed with just my fingers – and, the amount of oil needed was much less than the old JB Eliminator pump.
One very important improvement: I never, ever have to take it apart to clean dirty, slimy, oily gunk from the inside of the pump!
Recently, Harvest Right came out with a newer version of this pump.
The new pump had all the perks of the oil pump – including 7 CFM – and a 3/4 horsepower motor – using 218 Watts of power – at 2.1 amps.
The only change? A gate valve was introduced – which was a welcome upgrade from the old thumbscrew valve.
The Harvest Right Standard Vacuum Pump is extremely quiet running – with a noise rating of 64 dB. I’m here to tell you that I consider it “whisper quiet” after spending two years with the loud, tractor noises that came from the JB Industries Eliminator Vacuum Pump.
The Harvest Right Standard Vacuum Pump appears to be stronger than the Eliminator – getting the vacuum down below 500 mTorrs much quicker – and keeping it there much more consistently.
Harvest Right Premier Vacuum Pump
At a little more than 3 times the cost of the Harvest Right Standard Vacuum Pump – $895 – when this post was written – the Harvest Right Premier Vacuum Pump also runs with a 3/4 horsepower motor – at 7 CFM.
Being much better built, a deeper vacuum can be achieved.
Power usage is only 187 Watts at 1.7 amps – as compared to the Harvest Right standard pump’s usage of 218 Watts – at 2.1 amps.
The decibel level is only 52 dB – which is 12 dB less that the standard pump – making the noise level about the same as a refrigerator and quieter than most dishwashers.
This vacuum pump has a gas ballast – which keeps the water separated from the oil – allowing the oil to remain clean and clear.
The “oil mist filter” doesn’t allow oil mist to escape into the air – so my little sock trick – used on the HR Standard Pump – is not necessary unless you want to “err on the side of caution.”
Oil changes are only absolutely necessary every 20 to 25 batches.
NOTE: Use only premium high quality vacuum pump oil! Harvest Right recommends using either Robinair Premium High Vacuum Pump Oil or JB Industries Black Gold Vacuum Pump Oil. I don’t know which is better, but, since I bought a case of the Black Gold oil when I was running a JB Industries vacuum pump on my freeze dryer, I continued using the same oil when I got the Harvest Right vacuum pump.
If you don’t want to get involved with messy oil changes and filtering used oil, the Harvest Right Oil Free Vacuum Pump – with the same 7 CFM output – may be for you. But, it is pretty expensive – at almost twice the cost of the Harvest Right Premier Vacuum Pump – $1,695 – when this post was written.
This oil free pump does not require regular user maintenance.
The noise rating is 62 dB – which puts it just a shade under the noise level of the Harvest Right standard pump.
Since I am “neck deep” in Black Gold oil, I’ve not yet purchased an oil free pump as I’m still running my reliable, trustworthy Harvest Right Standard Vacuum Pump – so, I really can’t give an honest assessment of whether the oil free vacuum pump is worth the extra cash – or not.
Doing A Vacuum Pump Oil Change
Oil changes are pretty straightforward.
- I use a quart-sized Mason jar – held under the oil drain to catch all the oil. The jar is a little more than half full when the vacuum pump is completely drained. I use Mason jars since they are a bit sturdier and less prone to shattering than empty glass food jars.
- To catch the last few ounces of oil and particulates that collect at the bottom, tilt the vacuum pump slightly forward until there are only a few drips coming out of the drain.
- Then, after closing the oil drain valve, I add clean oil – by either opening a new quart or, by using filtered oil. Make sure that the oil level reaches the height of the oil level indicator on the vacuum pump cover.
- Since I like to ensure most of the old, dirty oil, water, and particulates are removed before the next batch, I run the vacuum pump for 10 minutes or so – drain the oil again – and refill the vacuum pump.
NOTE: It is NOT recommended to run the vacuum pump if the oil level is below the oil level indicator. Doing so will shorten the life of the vacuum pump by unnecessarily overheating it. Keep the oil level in line with the oil level indicator. Also, if the oil level is too high, the pump will expel excess oil.
Depending on how dirty the oil looks from the last oil drained, I may repeat this procedure 2 or 3 times.
Filtering Dirty Oil From The Vacuum Pump
Since I do multiple oil changes, I use a lot of oil during the oil changing process.
Which means I need reliable filters to clean the oil before the next use. And, to ensure the oil is adequately cleaned, I use a 4-stage filtering system.
There are two options for oil filters:
The first option:
Buy some Harvest Right Oil Filters – found in the Accessories section. At this time, they sell for $24.99 each.
Since I run a 4-stage filtering system, this option is way too expensive.
I don’t relish the idea of spending $100 for a filtering system – especially, when I’ll need to replace the filters when they start getting clogged up with gooey gunk!
The second option (my choice):
Simply make the filters out of discarded plastic containers. It ain’t pretty – but, it sure does the job – at a tiny fraction of the cost!
- Cut the bottom out of plastic half-gallon milk cartons, soda bottles, cooking oil containers, etc.
- Start with placing a double layer of coffee filters into the plastic containers – pushing them down close to the mouth opening.
- Fold up 8 or 10 sheets of paper towels and push them into the containers – against the coffee filters. It’s easier to do 2 or 3 layers of paper towels – folding 2 or 3 sheets at a time for each layer.
- I also add a layer of Diamond Media Premium Activated Carbon Granules between the paper towel layers – at least in the final filtering stage – if not all of them. This is the same activated carbon used for aquarium filtration systems. It aids in the removal of odors, discoloration, and helps to break down some of the particulates.
NOTE: Completely filtered oil will not look as pristine as new oil. It will be free of water and particulates – but, the oil will have a slight yellow tinge. The activated carbon granules will remove much of the yellowish tint, though.
Placing 4 of these homemade filters in some old Mason jars gives me my 4-stage filtering system at a small fraction of the cost of buying new Harvest Right Oil Filters –not more than a dollar per stage – the cost of the Mason jars and a few cents for the paper towels, coffee filters, and activated carbon granules. That’s a price you can’t sneeze at!
Once the oil filtering process is complete, I return the cleaned oil to my empty Black Gold quart containers – and the oil is ready to be re-used for the vacuum pump.
The filters will – over time – start getting clogged up with all the dirty gook being filtered out of the oil and making new filters will be necessary. You’ll know when it’s time to get out the coffee filters, paper towels, and activated carbon granules to make new oil filters because the filtering process slows down to a painfully slow drip, drip, drip…
There You Have It!
A messy job successfully completed. Nothing to it! If I can do it – ANYONE can!
Thoughts are welcome! Comment below or email me!