Jun Air Compressor Oil Guide – Choosing Oil, How Much to Use & Changing Oil

It can be quite a daunting task trying to figure out how to change your Jun Air compressor oil, how much to use and what the correct oil to use is right? Well, fear no more, I will answer all these questions in relation to Jun Air compressor oil for you.

Table of Contents

• What kind of Oil goes in a Jun Air Compressor?
• How Much Jun Air Oil to Use in a Jun Air Compressor?
• How to Change Jun Air Compressor Oil
• Reader Questions & Responses

What kind of Oil goes in a Jun Air Compressor?

It is extremely important to refer to your compressor manual before purchasing oil for your Jun Air compressor. We have a number of Jun Air compressor manuals on our brand page so please check here first!

The manual will tell you what Jun Air oil is compatible with your air compressor; if you cannot locate your manual, or we do not have it on our website, please contact Jun Air directly or visit their website to download a manual for your compressor.

Jun Air Compressor Oils on Amazon

Jun Air offers high-quality compressor oil that can help keep your compressor running smoothly. I have picked out a Jun Air compressor oil readily available on Amazon that could match your requirements.

Alternative to Jun Air Compressor Oils

A few alternatives to Jun Air’s own compressor oils are produced by Mobil. Again, it is very important to ensure the oil is compatible with your air compressor before putting it into the system, so please check first!

The first is the Mobil 101016 Rarus which is suitable for reciprocating air compressors whether single or multistage. This oil lubricant boasts excellent water separability, protection against rust and corrosion, long life for extended oil drain, and provides your compressor with very clean air valves.

The second is the Mobil 100870, boasting similar benefits as the previous oil but the potential to work with reciprocating, rotary screw, and rotary vane compressors.

Another option is produced by Powermate. It is the PX P018-0084SP 100% full synthetic air compressor oil, which boasts all-season performance for use in reciprocating air compressors.

How Much Jun Air Oil to Use in a Jun Air Compressor?

It can be difficult to establish how much Jun Air oil a specific model compressor pump requires without having the manual handy.

If you cannot locate your manual, I recommend contacting Jun Air directly or even searching the internet for the specifications of your Jun Air compressor and its model!

You should be able to obtain the manual for your model online, we have some available for download on our Jun Air Compressors page so check here first. This will provide the exact amount of oil lubricant you should put into your Jun Air compressor.

I cannot as easily give you an exact number on how much you need inside your Jun Air compressor, but I can give you tips on how to check the Jun Air oil amount inside your compressor and then describe how to change it.

Jun Air Oil Sight Glass

A sight glass is a way of gauging how much Jun Air oil is inside your air compressor. When checking your compressor sight glass you should look for a similar level of Jun Air oil as in the image below, where the Jun Air oil is roughly halfway up the red circle. This indicates that the compressor is suitably full!

Jun Air Oil Dipstick

Like in most engines, air compressor pumps sometimes do not have sight glasses, so instead, look to use the dipstick. These dipsticks can typically be found as part of the Jun Air oil fill tube cap and extend down into the sump and Jun Air oil.

The dipstick has markings that allow you to gauge the Jun Air oil’s level. To gauge whether you need to add more Jun Air oil, take the dipstick out, give it a wipe, and then “dip” it back into the sump and check the dipstick for what level the Jun Air oil is.

Alternative Method for Checking Jun Air Oil

It’s very common for compressors not to have a sight glass and maybe not even a dipstick. An alternative method is draining the Jun Air oil from the tank.

How to Drain Jun Air Oil From the Sump

Locate a plug at the bottom of the compressor pump housing to thread out, this in your Jun Air oil drain. You need to be careful so that dirty Jun Air oil does not spill over everything. Layout something underneath the drain to catch the mess that won’t be damaged by Jun Air oil leaking onto it.

Next you need to drain the Jun Air oil into a reservoir that will allow you to estimate how much Jun Air oil was in your sump already so that you can put an equal amount back in.

How to Change Jun Air Compressor Oil

Of course, changing Jun Air oil on every model of the compressor will be slightly different. Almost all reciprocating type compressors that are Jun Air oil lubed have similarities when it comes to changing their Jun Air oil.

First of all, ask yourself, is your compressor definitely Jun Air oil lubricated? If you aren’t sure, please check the manual for your model or contact Jun Air directly!

Changing Jun Air Compressor Oil Process

All lubricated compressors have a Jun Air oil sump located under the compressor pump housing. They should also have a sight glass, which will allow you to see how much Jun Air oil is inside the sump.

Follow the previously described steps to drain the Jun Air oil from the compressor and then screw the plug at the bottom of the sump back in, ensuring it is tightened securely.

Near the top of the Jun Air oil sump, there should be a port where you can add the new Jun Air oil. It’s hard to be any more specific than that as there are so many varying models of compressors, and many have quite different Jun Air oil-adding ports.

NOTE: Please be careful when filling the compressor with Jun Air oil. DO NOT put Jun Air oil into the air intake at the top of the pump housing port.

After you have replaced the plug at the bottom of the sump, add the replacement Jun Air compressor oil into the fill port until you’ve added the same amount you’ve removed. A little more than that amount should be OK, but avoid overfilling the sump.

Summary

The above methodology is simplified into the following steps:

1. Check the Jun Air oil level
2. Locate the plug beneath the sump
3. Drain the Jun Air oil into a reservoir
4. Tighten the plug back into the sump
5. Locate the Jun Air oil port
6. Refill the compressor with the same amount of Jun Air oil as was removed and remember to not overfill

Without access to every air compressor model’s manual, and assuming that the manual actually tells the reader what the Jun Air oil volume is, there is no way to be anything other than vague when providing advice about changing Jun Air compressor oil.

Reader Questions & Responses

Changing Jun Air Compressor Oil

Question

Old like new JUN-AIR COMPRESSORS. 20 & 23yr old silent oil-lubricated JUN-AIR compressor. I’ve recently decided to start back painting after a long hiatus. Inspired by my eldest artist/son I’m dusting off the ole equipment, airbrush equipment.

I own from new 2 JUN-AIR compressors. The 6-25/Maxi and the 12-50 JUN-AIR. I’ve only had to top off the oil on the most used 6-25 JUN-AIR and make a few minor maintenance repairs to the NON-RETURN VALVE. Replacing twice the spring and o-rings and the unloader valve.

What’s needed now is oil changes to both compressor units, Causing me to research my SJ-27F synthetic oil options as this is a senseless expensive maintenance requirement that is largely overdue largely because of the duration time 20+yrs.

The dilemma discussed on many JUN-AIR enthusiast threads like this is using the JUN-AIR OEM SJ-27F synthetic oil or finding another like the SJ-27F brand.

The JUN-AIR is sold in many places over the MSRP actually costs $50.00 for 16oz direct from JUN-AIR.

My issue is I would need 5 16oz bottles $250.00 worth before shipping cost.

I searched online and came across some other brand options on Amazon.com.

I ended up calling one of the sellers Dental Planet.COM spoke with a helpful parts & service support rep who has assured me that the alternate DCI SJ-27F synthetic oil brand type was the most commonly sold brand and also comes in 24oz bottles and sells for $45.00 a bottle. So I have opted to purchase 3 bottles and I am awaiting my delivery.

I have included some pics of my units for viewing, enjoy. I will be back with my results and more pictures. Thanx for listening.

Response

Thanks for the news, and the photos, and we are all looking forward to your results with the DCI SJ-27F synthetic oil.

If you wander back in the comments and posts, you will see that others have used alternate oils in their Jun-Airs in the past.

Response

I was poking around on this subject, and see that at least the newer Jun-Airs don’t use rings on the pistons – do you know if that’s the case with your units?

Questioner

No, I’m just doing maintenance.

I’ve had my compressors for a long time 20+ years and they still run like new. Though I’ve not used them in 12+years I’ve kept them in very good condition.

Now that I will be using them again an oil change is needed and overdue, though I can’t tell by the way these compressors operate today.

It’s really a precaution as the JUN-AIR OEM SJ-27F synthetic oil currently running in each of my compressors has done an exceptional job lubricating the JUN-AIR 6 motorheads.

I just felt that the synthetic oil brand change to DCI came as a matter of cost and value. I’ll be doing the oil change this weekend on the 12-50 1HP model and hoping to do a time-lapse video oil change “How To” as many YOUTUBE searches on JUN-AIR lubricated compressor maintenance have been nil.

Response

Re this: “hoping to do a time-lapse video oil change “How To”, if you do so Nigel, and wish it so, send me the video URL and I’ll add it to the Jun-Air page.

Questioner

JUN-AIR 6-25 DCI/SJ-27 OIL CHANGE
by: Nigel

Oil change video:

(Thank you Nigel. Your video has been added to the Jun Air main page as well.)

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Jun Air Compressor Oil Search

Question

I am looking for any info related to a 1972 Jun-Air Model 6 and what is appropriate oil to use/where to get it.

Any other pointers to DIY support to maintain and/or rebuild are also greatly appreciated. The compressor is a USA model with a 15-liter tank under it and a .5HP motor.

Response

The specs call for SJ-27 synthetic compressor lubricating oil.

Complementary alternatives are available: SME 7050 Synthetic Compressor Oil SJ-27 Compatible 24oz

You can browse for the most competitive source for lube oil.

Typically the model 6 also had a suffix, such as 6-4 or 6-15. Can you determine if your model has such?

Questioner

The labels only show Model 6 without any -XX after. Since it is mated to a 15-liter tank, would that imply a 6-15?

The oil indicated on the label on the unit is SB-420IL. Is there a cross-reference for this?

Response

As noted earlier, the specs call for SJ-27 synthetic compressor lubricating oil. Since that is the recommended oil for Jun-Air compressors, by Jun Air, I can only assume it would suit your compressor.

An email to Jun-Air wouldn’t hurt, I would say.

Re: 6-XX, could be. There is no sign of just a Model 6 in today’s lineup at Jun Air.

Questioner

The regional rep. said that they only have the SJ-27 and did not know what the specs were for SB-42, the original oil spec back in 1972. Bambi still has oil they call SB-42/46 available in the UK. I am going to try the SJ-27 and see if it works OK.

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If you have any questions regarding Jun Air compressor oil, please leave a comment below, with a photo if applicable, so that someone can help you!