by Tom Gaylord
Writing as B.B. Pelletier
Today’s report is written by reader Ian McKee, writing as 45Bravo.
The world is shifting over to precharged pneumatics (PCP) in a big way, and that means more of us are needing compressed air. 45Bravo got an Omega Supercharger air compressor that had a couple issues from just sitting around. Today he tells us what he did.
If you’d like to write a guest post for this blog, please email me.
And now, over to you, 45Bravo.
This report covers:
- It works-sort of
- Talk to Todd
- Bag O’ Spares
- Basic trouble shooting
- No lights
- The lights are on, but the compressor won’t start
- Compressor not building pressure
- Pressure gauge/auto shutoff
- Bleed valve service
- Water pump not working
- Air/water separator auto purge system
- The main piston assembly
So, you bought a PCP compressor that has been sitting in a closet for 4 years, what should you do? That’s exactly where I found myself.
Even though this is about the Omega Supercharger, many of the things that need to be checked or changed will apply to other brands of PCP compressors.
It works-sort of
When I got it it ran, it pumped air, the water pump worked. But since it had been sitting without being operated for so long, what had possibly gone wrong that needed to be addressed?
Mine would not build pressure past 1700psi, so I knew I had a significant leak somewhere. After some searching and spraying some soapy water I found the air/water separator/auto purge system was not sealing completely in the closed position, and was leaking from the vent line. I will go through the rebuild of that in a moment.
Talk to Todd
After talking with Todd, the support technician for Omega, the pump system needs to be used regularly, or the o-rings will dry out and need service. So if you are not using it regularly, just run it for 5-10 minutes every couple of weeks or so.
Bag O’ Spares
When you bought the compressor, there should have been a bag with spare o-rings, a burst disk and other parts. This compressor was one of the first produced, in 2014, and it was not shipped with the parts kit.
If you have lost yours, the entire replacement spare parts kit is available for $65.
If your main piston is leaking, parts for that are in the spare parts kit, but if you don’t feel qualified to rebuild it, Omega offers a piston rebuild service for $150, and they pay shipping back to you.
Since the system has a port to lubricate the main piston and o-rings during use, the main piston o-rings in mine were well lubed and still functional. But we are airgunners; we can swap some o-rings can’t we?
After fixing the air/water separator, and the compressor was able to get above 4000 psi, I found that some other o-ring rings in the high pressure system had dried out and were leaking, so we will go through each part as to what needs to be done, how to do it and some tips on things to look out for.
Remove the 6 Phillips head screws on each side of the compressor’s side covers; the shorter screws go in the bottom of the covers.
Tip: The heads of the gold-colored Phillips screws damage easily so be careful, I replaced the screws with stainless steel Allen head cap screws from Home Depot. They are size 10-32. The shorter ones are 1/2-inch and the longer ones are 3/4-inch.
TAKE PHOTOS OF EVERYTHING before you start. Especially photograph the electrical connections to the parts, and their places where they connect to the control board.
TIP: The flexible high pressure hoses have a fixed end on one end. Tighten this end first. The other end of the hose that has a female end should to be tightened last.
The o-ring sizes are not listed in the manual, nor in the parts breakdown, the o-rings that I used to replace the ones on the ends of the flexible and fixed high-pressure lines were a size 008.
Basic trouble shooting
Make sure there is power going to the unit.
Make sure the red circuit breaker on the front isn’t tripped.
Take the side panels off and look for lose wires on the control board.
The lights are on, but the compressor won’t start
There is air in the flow switch. Make sure there is water in the tank, and no air in the lines.
Wires from the flow switch may be loose.
More on this is covered below.
Compressor not building pressure
Make sure the bleed screw is tight, as the compressor builds pressure, you may have to tighten it more.
Check the burst disk for damage; (is air coming out of the tiny hole)?
A replacement disk is in the parts bag.
Tighten the fitting to a firm snug.
Check the main check valve, (use a 19mm wrench to remove the brass fitting the burst disk sits in). Look for a burnt or dirty check valve, clean the hole where the valve is located; replacement valves are in the parts bag. Place small end of spring on valve and center it, replace the brass fitting, tighten snug.
Omega Supercharger check valve.
We will be starting with the easiest fixes and working towards the hardest. This first one is very simple, but VERY important!
Pressure gauge/auto shutoff
This gauge is used on most of the compressors that have an auto shut-off feature, so what I’m about to tell you applies to many compressors.
It only has 2 connections, one is a flexible high-pressure hose fitting with an o-ring in each end, and the other is the electrical plug that connects it to the control board.
Be careful of this connection when working on the compressor, as it is easily jostled, and the high pressure shut-off will not make electrical contact to shut off the compressor when the desired max fill pressure is reached.
ALWAYS check this connection last after working on anything inside the compressor. And test that the auto shutoff works before closing the case.
The high pressure air connection is shown by the pencil, the electrical connection is right above it.
Bleed valve service
Remove the pressure relief valve knob from the unit, then remove both Phillips screws holding the block in place, remove the 2 flexible high pressure hoses with a 14mm wrench or a crescent wrench. Remove the clear vent hose by depressing the blue collar and removing the clear hose.
Clean and lube everything lightly with silicone lube, put new o-rings in the connections of the high-pressure hoses, and reassemble and test.
Bleed valve knob in the compressor.
The bleed valve has been removed from the compressor.
O-ring in high pressure air hose.
Water pump not working
Above the water pump is a water control flow valve. If there is air in the line, it will not let the water pump run.
Make sure the electrical connection is plugged into the control board, and no air bubbles are in the line.
You can rock the machine forward and backwards, to move the water into the control valve, or you can remove the hose above the control valve and let the water flow into the valve.
If there is water in the control valve and the electrical connections are good and the pump still does not run, using a volt meter, see if 12v DC is going to the pump, if there is no voltage, check the wires and connections to the control board. If you do have 12v coming to the pump, replace the pump.
If your cooling water is cloudy, you can drain the system. Then refill with purified drinking water, NOT DISTILLED water.
Omega also says to add 1oz. (30ml.) of regular automotive coolant to the system. If you are going to be keeping the pump in the house at room temperatures, it is not necessary to add the 1/2oz. (15ml.) of the Royal Purple additive to the system.
If you choose to include the Royal Purple additive, it is available from most automotive stores.
Water pump (blue) and flow valve (white thing above it).
TIP: when loosening the high pressure lines, use 1 wrench to hold the fitting, and the other wrench to turn the connector on the end of the high pressure line.
Air/water separator auto purge system
This was where my major problem was. Take photos of the 3 wires that connect to the black solenoid at the bottom of the air/water separator, so they can go back where they came from.
Using two 14mm wrenches, (2 small crescent wrenches will work also) loosen the 2 high-pressure air lines that attach to the bottom of the air/water separator. Be careful as there is a size 008 o-ring inside the connector of each line that will need to be replaced when assembling.
Remove the air output hose, being careful not to damage or lose the Dowdy seal (also called a bonded washer), and remove the large nut on top that holds the assembly in the case. Then remove the small Phillips screw next to it. There is a clear vent hose that is disconnected by pressing the blue locking collar back to the plastic fitting and the vent hose easily comes out.
The pencil points to the 2 high pressure lines at the bottom of the air/water separator solenoid, there is an o-ring in each hose that should be replaced.
Remove the black nut from the rear of the solenoid, and slide the solenoid off of the shaft, Using a piece of leather or rubber between your pliers to protect the shaft, loosen and unscrew the metal shaft from the unit, being careful of a plunger and spring that are inside the metal shaft.
The black solenoid is off the air/water separator.
With the solenoid off the shaft, grab the shaft with padded pliers, unscrew it and pull it out from the air/water separator. See the parts that come out.