The compressor provides service to a small machine shop and two Electronic labs. The draw on air from the Electronic labs is almost negligible as per the type of work done there. The machine shop can go several days without drawing air-again depending on work load.
One morning the compressor case was quite warm so I shut the entire compressor off. In reading through the trouble shooting guide it seemed the intake filters may have needed replacing.
I drained the entire system and replaced the intake filters but the compressor was still taking along time to pressurize. After a visit by Charlie Hamilton of RM Wright Company- a Jun Air Dealer, it was determined that the next step was to replace the Check Valve.
Here is the original Check Valve.
Here is the original Check Valve taken apart-Can't really tell that there is anything wrong with it but I ordered a new valve and installed it (June 5)
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I drained the entire system again and replaced the check valve. I turned it on to re-pressurize the system. I was only charging the tank at this point-not the lines. The cycle should shut off at @125 psi. It took 45 minutes to get to 75 psi at which point I shut off the compressor. This seems to be an excessive length of time for re-pressurizing the tank. I have checked for leaks and did not find any-Seems that there is difficulty with air getting into the tank. The tank holds pressure over night as I shut it off and it remained at 75 psi. The Jun-Air tech manual suggests that the Piston Rings may be worn and are causing a slow pressurization. So I have taken apart one of the two motor/Pump units.
Here is the newly installed Check Valve.
Here is a view of one of the dual cylinder head pumps.
Here is a view of the other dual cylinder head pump with the heads removed.
Here is the right head showing the gaskets/valves that separate the two halves of the head.
Here is the same piece (-gasket/valve flipped).
The pistons have a set of five spring loaded rings.
The spring loaded rings may need replacement.
One of the four new Intake Filters
Alan,
Without much doubt your problem lies in the valves. As long as you have it apart you might as well also do the rings, there are kits available for both.
6284500 ring kit for model 2000, $182.21
5470000 valve kit for model 2000, $269.41
You will be amazed at the difference after installing. These are normally 2-3 week lead time items but we may be able to expedite. I wish all my customers provided such excellent information!
I sent all of this information to Charlie Hamilton at the RM Wright Co. He replied:
Our compressor is a 4000M-150B so it has two motor/pump units which would require two of each of the kits listed above in red for a total running over $900. At this point I'd like to know that replacing the rings and valves will assure a properly running unit-$900 is a lot to spend-can you give any further assurance that replacing these parts will return our compressor to optimum condition?
-Alan Young
This is a file documenting a series of steps taken in troubleshooting a slow pressurization cycle for a Jun-Air Model 4000M-150B air compressor.
"The unit was put together in Wooddale ILL before we bought the JUN-AIR line.
The Label on the outside cabinet should read 4000-150MD3 the M stands for metal cabinet, the D for dryer and 3 for the dryer size. The dryer is the long black on item on the outside of the cabinet"
Ed Gruss,
Technical Assistance
Gast Systems Solutions
269.934-1116 (phone)
800-331-3289 (fax)
www.gastmfg.com
www.jun-air.com
www.idex-hs.com
On 6/13/2013 I took apart the two interior check valves and removed the flexible hose connectors Click this link to see more information on the Check Valves.
