Sanborn Air Compressor Overheating

[Falthead]

Just picked up a 1983 5hp 230v single phase twin cylinder single stage Sanborn air compressor. Just wired it up and ran it up to full pressure and the head of the pump started to get extremely hot and give off smoke. The air tube leading into the tank also was quite hot.
The pump is full of oil. What should I be looking for?

 

[pgreen]

Depends on how hot. Compressing any gas creates heat. The tube between the head and the tank will always get hot. The head will also.

Is it covered in dust or oily residue from sitting? If it has sat for a while and not run, it could have picked up enough junk that is burning off with the heat from the compressor head.

I don't know what the "normal" temperature of the head is, as I haven't checked mine. But, I know not to touch it when running or soon after also.

 

[smooth72]

Just picked up a 1983 5hp 230v single phase twin cylinder single stage Sanborn air compressor. Just wired it up and ran it up to full pressure and the head of the pump started to get extremely hot and give off smoke. The air tube leading into the tank also was quite hot.
The pump is full of oil. What should I be looking for?

They always get real hot when first airing up or running hard. So hot if you touch it would badly burn you, speaking from experience. The smoke could be something that got on it and just burning off.

 

[s_ontario]

just make sure its not over filled with oil heat it up again a change it out to a good synthetic oil
they do run hot to hot to hold onto for sure

 

[Falthead]

Thank you for the quick replies! I was concerned that there maybe something wrong with the pump-it sat idle for quite awhile before I purchased it. Going to clean it up good and paint it, then replace the oil.

 

[pgreen]

Another vote for synthetic oil in your compressor. I put Royal Purple in mine, just because that is what I had at the time.... My compressor actually ran a bit smoother and quieter.

A quart or so of synthetic oil is low $$$ for something that will not likely get regular oil changes. Yeah, I'm sure some on here change their compressor oil every 3 months or 30 hours of use, but most people never change it...

 

[wineslob]

Whats the "full pressure"? and did it unload/shut off like it should at that pressure?

 

[Falthead]

Full pressure is 120 psi and it did turn of. The other end was 90 psi and it turned back on fine.

 

[hetkind]

those numbers sound right...as for oil changes, once a year on my IR 2340, a single phase, dual stage, 240v unit, per instructions manual.

To change the oil every 30 hours of use seems very excessive for a piece of fixed shop equipment...in heavy use, that would be once a week. My unit has a 100% duty cycle.

Howard

 

[wineslob]

Full pressure is 120 psi and it did turn of. The other end was 90 psi and it turned back on fine.

How long did it take to get to full pressure? If only a few min, it sounds OK. It may have had stuff on the head of the compressor that "burned" off from sitting.
One compressor at work, an old G/D unit, had a outlet temp of 400 degrees. It was 40HP, but even the small units can get just as hot.

 

[Falthead]

From empty to 120 psi took a good four to five minutes-didn't seemed to work too hard either. I ran it up again from empty-ran the same but did not smoke-you're assumption that it was dirt and oil from sitting seems on the mark. This is my first real compressor and I bought it without hearing it run and was just a bit concerned not knowing how the po maintanenced the machine or even if it was in working order at all.
Thanks for the goood advise.
Tony

 

[smooth72]

Now run you air line pipe all over the garage and enjoy. Once you have a compressor and start buying air tools you will wonder how you did without. Also I would extended your drain out to make it easy to drain, that way you will do it often. Speaking from experience, it becomes an addiction, and I don,t want a cure.

 

[Lhorn]

I've heard of people using synthetic. Is this synthetic compressor oil or synthetic motor oil? I've never seen synthetic compressor oil but suspect that it may exist. I've heard not to use regular motor oil, so I'd guess that this would apply to synthetic motor oil as well since it likely contains the same detergents.

 

[smooth72]

I used synthetic oil made for compressors.

 

[Zrexxer]

I've never seen synthetic compressor oil but suspect that it may exist.

There are dozens of synthetic compressor oils. Royal Purple Synfilm, ChampLub Synthetic, Mobil Rarus 800 series, Chevron Syntholube, the list goes on and on.

 

[Lhorn]

Sounds good. I'll have to look a bit harder next time.

 

[engineer2]

Just in case anyone didn't know, you should use non-detergent oil in a splash lubricated compressor. If you use Royal Purple, use their Synfilm Recip. 100, not their motor oil.

If your compressor is running hot, you might want to pull the tank check valve and either replace it, or clean it out. It might be partially clogged or leaking. If it's a 2-stage, make sure the reed valves are in good shape. Easy enough to check these items.

If it were mine I would rig up an old computer fan up to have it blowing on the cylinder head.

 

[wineslob]

I've heard of people using synthetic. Is this synthetic compressor oil or synthetic motor oil? I've never seen synthetic compressor oil but suspect that it may exist. I've heard not to use regular motor oil, so I'd guess that this would apply to synthetic motor oil as well since it likely contains the same detergents.

In recip compressors I've used nothing but motor oil. ND 30 wt was just fine. Many of these machines were from the 40's and 50's and were still going strong last I heard.
In rotary machines I've seen everything from ATF to Syn's that cost $80+ a gallon.