Compressor - New GX CS4 Performance Issues!

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Don_Fabb

Don_Fabb

Member
Mar 29, 2024
19
30
Texas, USA
Hi,

I have recently purchased a GX CS4. I have about 4-5 hours of use with it. When I first purchased the unit I did upgrade the connecting hose for charging to a longer one (about ~3 feet long) and the dead head tests were about 1 minute for 300 bar fill (vs. the 38 seconds per the manufacturer). This made sense to me because it's a longer hose with roughly twice the length and volume of air to fill and the performance was great while filling Air Rifles only.

One month later and I have noticed that it's not performing at that same level of 300 bar per minute of dead head tests. Last night, and this morning I have done three dead head tests and the machine is now filling at a rate of 2.5 to 3 minutes per 300 bar fill. That's three times slower than a month ago. So, I went ahead and turned the grease knob one full revolution. When turning the knob I sensed very little resistance almost free spinning, and stoped when I felt resistance at about one turn in.

Are there any known issues of what may be causing this degraded performance with my brand new GX CS4 unit that you all may be aware of?

Have a great day, and any help or guidance is much appreciated!
 
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Don_Fabb said:
Hi,

I have recently purchased a GX CS4. I have about 4-5 hours of use with it. When I first purchased the unit I did upgrade the connecting hose for charging to a longer one (about ~3 feet long) and the dead head tests were about 1 minute for 300 bar fill (vs. the 38 seconds per the manufacturer). This made sense to me because it's a longer hose with roughly twice the length and volume of air to fill and the performance was great while filling Air Rifles only.

One month later and I have noticed that it's not performing at that same level of 300 bar per minute of dead head tests. Last night, and this morning I have done three dead head tests and the machine is now filling at a rate of 2.5 to 3 minutes per 300 bar fill. That's three times slower than a month ago. So, I went ahead and turned the grease knob one full revolution. When turning the knob I sensed very little resistance almost free spinning, and stoped when I felt resistance at about one turn in.

Are there any known issues of what may be causing this degraded performance with my brand new GX CS4 unit that you all may be aware of?

Have a great day, and any help or guidance is much appreciated!
Click to expand...
I have a new CS4-i with about 3 hours on it. So far, so good.

I've read that one should not use the auto shut off feature. Apparently, there is less stress on the compressor if the bleed valve is opened while the compressor is still operating. Leave the bleed valve open and allow the compressor to run for a few minute under no load. Turn off the compressor but allow the water pump to operate for a few more minutes before unplugging the machine.

I hope I'm following the correct procedure because it would be very disappointing to have my new compressor's performance drop off after 5 hours of use.

Another video suggested allowing the compressor to run under no load for a few minutes after rotating the grease knob but before conducting a dead head test. This is weak suggestion but perhaps it might work for you.

JackHughs
 
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I have a CS4 with less than 3 hours. So far it has performed flawlessly. I turn it on and give the water a little bit to check for proper flow. Then after hooking up the fill hose I hit the start button and let it run "unpressurized" for at least 60 seconds before tightening the bleed screw. I have always had it stop with the gauge cut-off and then immediately purge the bleed screw. I installed an external temp gauge and I let the compressor run the water pump and fans until the temp goes back down to the starting temp before filling. As far as the grease pot screw. There are a bunch of posts here stating that it really needs to be taken off , turned upside down and the screw turned until the grease is level or almost level with the bottom of the grease containment pot. Then screw it back on after making absolutely sure the rubber washer in the bottom is put in the correct place. There is a tiny pin hole in the center of the rubber washer that has to be over the hole in the bottom for the grease to flow through when turned and enter the compressor. Sorry to hear your having pressure building problems.
Ray
 
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"Get in to airguns they said. It will be fun they said.
Get a big bore + get a compressor = lots of fun" :LOL:
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Thank you all of the replies. The CS4 now cannot pressurize above 50 bar, stuck in a loop it seems and unable to even complete a dead head test.. It's unfortunate how from one day to another the unit just completely stopped performing. It was my concern when purchasing the unit after spending so much on it how good will the support be. It's beyond me how is it that after a few fills the unit is failing. This wasn't an Ali Express or eBay purchase I've heard there are a lot of counterfeit machines sold on there.

Hopefully you all do not share the same experience :(
 
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JachHughs said:
I have a new CS4-i with about 3 hours on it. So far, so good.

I've read that one should not use the auto shut off feature. Apparently, there is less stress on the compressor if the bleed valve is opened while the compressor is still operating. Leave the bleed valve open and allow the compressor to run for a few minute under no load. Turn off the compressor but allow the water pump to operate for a few more minutes before unplugging the machine.

I hope I'm following the correct procedure because it would be very disappointing to have my new compressor's performance drop off after 5 hours of use.

Another video suggested allowing the compressor to run under no load for a few minutes after rotating the grease knob but before conducting a dead head test. This is weak suggestion but perhaps it might work for you.

JackHughs
Click to expand...
This makes sense in away there would be less back pressure on the machine the less time its holding the pressurized load. I appreciate your response.
 
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My CS4-i was fine at first. Then started to work a bit slower, and took a tad longer to reach full pressure.
I did the soapy water trick and found that the side mounted burst disc fitting was leaking air. This is the complete fitting where it threads into the main block and also the small 'cap' that screws on to it to hold the burst disc in. So 2 points of air leak in the one fitting.
Used some thread tape and that sorted one part of the problem. It was now faster to fill my 220cc gun cylinder but still would lose pressure once the gun cylinder was filled and the pump stopped.
Although I couldn't see any air leaks with the soapy water (probably not 'soapy' enough), I took out the 2 front mounted fittings...the drain valve and the air outlet.
Both did not have what you could call 'finely finished' threads, and there was some small amounts of fine metal swarf in there too (parts not cleaned after machining and just screwed in).
Cleaned the threads, bunged on more thread tape, screwed it all back together again.
Success...pumps up as quick as it used too, and no pressure leak when full.
So maybe just check those fittings on yours?
 
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I find after using the Gx cs4i for a couple weeks and today running it for 5 hours straight to fill a 9 liter tank from empty that I have no fear of operating it as designed. It is a very convenient, cool running, quiet ( relative ) , and walk away to other
activities ah back to convenient I guess.
I did get a temp gauge from amzon today. I’ll have to open it up to find a place for the probe. Now just curious. I think after today’s run I could tell by touch if something was wrong heat wise. Warm a little but hot definitely not.
So glad I bought.
 
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Guys I solved the problem with the compressor. As some of you stated I removed the cover and checked for leaks throughout the unit, and I didn't find any. Then, I removed the burst disc assembly that's right next to the grease pot. I found that the burst disk assembly was both the small screw in the top was loose, and the assembly internals was extremely dirty with filth and oil. I went ahead and cleaned all of the components, and even inside the assembly intake hole with a q tip. I put together all the components back in making sure it's all tight and secure. Turned on the unit and performed another dead head test and noticed the time improved from the horrendous 3 minutes per 300 bar fill. I performed a second dead head test and this time the unit is back down to baseline dead head rates of 300 bar fill per 54 seconds with the longer 3 foot hose.

Thank you all of your suggestions and tips to troubleshoot the GX CS4. This thing is a workhorse of a machine :)
 
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UPDATE: Just wanted to let you know and specially the ones that have a CS GX4 without an hour meter. The first hour meter I purchased that isn't wired to the unit but works off vibration was not sensitive enough to react and start the clock accurately. The second one I have purchased shown below is a few dollars more off amazon and works like a charm. I've used it for about an hour and is sensitive enough to accurately start the clock to collect the run times off the compressor while operating. I highly recommend this hour meter and the best is that it does not have to be wired. I am posting the link to it below for your reference. And, thanks again for you all on this tip!

 
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Hate The Rain said:
Unfortunately, I have joined the ranks of a poorly running CS4. Got about 4 good hours out of it, now it won't go above 2350 PSI. I seems to load up and barely run the piston? in the compressor before it turns itself off. Has anyone ever gotten/found a manual for these things?
Click to expand...
Have you checked the grease cup for air bubbles? It may be that your CS4 is starved for grease.

There is no manual. The only thing GX provides is the pamphlet shipped with the compressor.

JackHughs
 
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Whale poop. Grease system checks out fine. Plenty of grease and the hole is open on the black "gasket" inside. Just cleaning out all the valves at the moment. So far, a bunch of black greasey goo around most everything. Cleaned that all up. I'll work my way from the front to the compressor. Should be easier than trying to get the warranty to happen. If it still doesn't work, I'll have spare parts for everyone.
 
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Hate The Rain said:
Whale poop. Grease system checks out fine. Plenty of grease and the hole is open on the black "gasket" inside. Just cleaning out all the valves at the moment. So far, a bunch of black greasey goo around most everything. Cleaned that all up. I'll work my way from the front to the compressor. Should be easier than trying to get the warranty to happen. If it still doesn't work, I'll have spare parts for everyone.
Click to expand...
Check out this post (#291) about the check valve...similar to what u describe.

GX CS4 Compressor - Initial Impressions

2 burst disks is the same as not having a safety system. You dont know what the burst pressure is. Not safe. If they are bursting early it may be an overtightening issue. GX official contacted me and is sending me some 400 bar burst disks for free. I also purchased a bag of 5 of the same so...
www.airgunnation.com www.airgunnation.com
 
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