Old Nelson Vacuum Pump

[glxpassat]

I have an old Nelson model 911s belt-driven vacuum pump that I inherited from my Father. I seems to work fine but there's no telling how old the oil in it is. I saw one ad where they are capable of 10 microns. A comment on Youtube stated these old units used 30w compressor oil. The label states to use Nevaco #717 oil.

When I google it, the results for other brands of 717 show up and it seems they're made to work with ammonia refrigeration systems. I would only use it on vehicles, typically R134, and was wondering if any 30w non-detergent mineral oil would be ok or if I should spring for a 30w fluid made specifically for vacuum pumps. They're not cheap and hard to come by. Anyone have experience with these?

Thanks for any help, similar unit on ebay here.

 

[kschachn]

That’s similar to the Welch vane pump I have. I wouldn’t use motor oil in it, get some vacuum pump oil on Amazon. I think even NAPA sells it as well. You need an oil with the proper vapor pressure.

 

[Boomer]

Any laboratory supply outfit should handle vacuum pump oil.

 

[b4autodark]

You can get vacuum pump oil anyplace that sells supplies for dairy farmers.

 

[oil pan 4]

Yeah use something like an iso100 vac pump oil.
Worst case scenario use a r-134a oil.
That 717oil is ammonia compatible oil, no reason to use it unless you're doing ammonia, it will just be harder to find.

 

[Chris142]

I bet that you can go to any auto parts store and use the vacuum pump oil they sell for auto ac.

 

[Fitter30]

I have an old Nelson model 911s belt-driven vacuum pump that I inherited from my Father. I seems to work fine but there's no telling how old the oil in it is. I saw one ad where they are capable of 10 microns. A comment on Youtube stated these old units used 30w compressor oil. The label states to use Nevaco #717 oil.

When I google it, the results for other brands of 717 show up and it seems they're made to work with ammonia refrigeration systems. I would only use it on vehicles, typically R134, and was wondering if any 30w non-detergent mineral oil would be ok or if I should spring for a 30w fluid made specifically for vacuum pumps. They're not cheap and hard to come by. Anyone have experience with these?

Thanks for any help, similar unit on ebay here.

No motor oil only vacuum pump oil. The moisture that is pulled out raises vapor pressure that destroys oil. High vacuum can't be made and the sealing properties are gone. Oil change is needed every use if the pump isn't used very often or while using turns milky ( moisture).

 

[kschachn]

Also make sure you understand how the gas ballast works when you’re using it on a condensible gas like R-134a.

 

[glxpassat]

Thanks for the replies, everyone! I guess my biggest concern was the correct viscosity. I knew I could find vacuum oil at the local store, but most of it is thinner oil and I just didn't know if these old units used something thicker, like iso 100. An iso 100 vacuum specific oil is harder to find, Grainger shows a few, though not cheap.

 

[Vincsant]

I have an old Nelson model 911s belt-driven vacuum pump that I inherited from my Father. I seems to work fine but there's no telling how old the oil in it is. I saw one ad where they are capable of 10 microns. A comment on Youtube stated these old units used 30w compressor oil. The label states to use Nevaco #717 oil.

When I google it, the results for other brands of 717 show up and it seems they're made to work with ammonia refrigeration systems. I would only use it on vehicles, typically R134, and was wondering if any 30w non-detergent mineral oil would be ok or if I should spring for a 30w fluid made specifically for vacuum pumps. They're not cheap and hard to come by. Anyone have experience with these?

Thanks for any help, similar unit on ebay here.

I too have an old Nelson model 911 vacuum pump that was my father's, I used it many years ago, it's got to be at least 65 years old. I just recently disassembled it to clean out the old oil, found a lot of caked on rust, sludge and very thick nasty looking oil. Fortunately, the sludge was at the bottom and the vane pump and wiper was not rusty and showed little ware. The shaft seal was a Victor, and I crossed it over to Timken seal #340771. Anyway, what oil did you finally decide to use? #717 oil spec shows that has an ISO 68 which will come close to gear oil viscosity of 80W. www.nextlubricants.com/en/products/next-717/

 

[Vincsant]

I contacted Texas Vacuum Pump company LLC. They recommend their oil #TVP68 $102.15 Per gallon, (may sell for $62.50 per gallon).
https://texasvacuumpumps.com/oil/lubricating-fluids
Sounds a little pricey but at $62.50 gallon that will give you 8 changes, not bad.

 

[glxpassat]

I too have an old Nelson model 911 vacuum pump that was my father's, I used it many years ago, it's got to be at least 65 years old. I just recently disassembled it to clean out the old oil, found a lot of caked on rust, sludge and very thick nasty looking oil. Fortunately, the sludge was at the bottom and the vane pump and wiper was not rusty and showed little ware. The shaft seal was a Victor, and I crossed it over to Timken seal #340771. Anyway, what oil did you finally decide to use? #717 oil spec shows that has an ISO 68 which will come close to gear oil viscosity of 80W. www.nextlubricants.com/en/products/next-717/

I just ended up using the Supercool oil from Advance Auto, I believe it is an iso 68. It seemed to work fine, my friend's ac blew very cold after I got it charged up. I don't use the pump often, if I did I would probably try to find an iso 100.

 

[glxpassat]

I contacted Texas Vacuum Pump company LLC. They recommend their oil #TVP68 $102.15 Per gallon, (may sell for $62.50 per gallon).
https://texasvacuumpumps.com/oil/lubricating-fluids
Sounds a little pricey but at $62.50 gallon that will give you 8 changes, not bad.

Thanks. I noticed they also sell a TVP77 that is a thicker viscosity and explicitly called out for rotary van pumps. I'm curious why they didn't recommend that one.

 

[Vincsant]

I think any of the "high vacuum" pump oils would work fine, and my pump worked well pulling a good vacuum, however, since that time I sold it. The spec calls for #717 with ISO 68, #717 oil is used for ammonia systems, both oils are ISO 68, my guess would be that TVP77 would be for non-corrosive applications and the TVP 68 being a synthetic would better suit a pump exposed to a more corrosive application. I don't know for sure, just my thoughts, but, if you are not using it for an ammonia system, I'm sure you would have no problem using the TVP77, or any of the "high vacuum" pump oils.

 

[kschachn]

I think any of the "high vacuum" pump oils would work fine, and my pump worked well pulling a good vacuum, however, since that time I sold it. The spec calls for #717 with ISO 68, #717 oil is used for ammonia systems, both oils are ISO 68, my guess would be that TVP77 would be for non-corrosive applications and the TVP 68 being a synthetic would better suit a pump exposed to a more corrosive application. I don't know for sure, just my thoughts, but, if you are not using it for an ammonia system, I'm sure you would have no problem using the TVP77, or any of the "high vacuum" pump oils.

Lots of suitable name brand oils on Amazon.