GX CS4 Compressor - Initial Impressions

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Camaro454 said:
Your brother might not realize how long the compressor will run filling a gun direct. I fill my guns exclusively from my compressor both to 250 and 300 bar. The killer for this and any compressor is heat notwithstanding poor manufacturing tolerances and or materials. Filling a bottle will almost always require a longer run and in some cases require a cool down cycle before complete fill. I would monitor temperature at all times and use best practices in your maintenance.
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Thanks- My logic was that the larger CS4 compressor would have to work less to fill my guns directly hence increasing the longevity of the compressor. I follow maintenance. I did invest in the temp and hour timer mentioned in the thread, Seemed like simple key information one should have.
 
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Hi All, Update on my CS4- I drained the water that came with the unit and flushed the system 3 times with distilled water. Then I filled the reservoir and began to perform the line test at 300 bar. The pump would not go above 220 bar and when off it leaked. I bleed the line and set the limit to 200 bar. The pump did not stop at 200 and went to 220 and the needle bounced and stays like that until I shut it off. I know I have a leak because when I shut it off, the pressure has a steady drop. Yes, I can take off the cover and look for a leak but the pump is freaking brand new. Also, one of my gauge needles is not red as in the picture in the thread. With that said any advice?
 
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First check the rupture disc is not loose.

Then check the the bleed off screw is very tightly closed. If the threads on the bleed screw get any contamination you will not get a good seal. Light touch of Emory cloth to clean grit.

There is a ball seal that gets residue buildup after several hours of use. It may be dirty from assembly. There is a 19mm (maybe 17mm) brass bolt on the bottom of the unit. Remove that bolt, pull out the plunger ball and spring. Make sure rubber ball is clean. Reassemble.

If you have to go beyond those three easy checks, please post up. Let us know what you find.
 
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JimNM said:
First check the rupture disc is not loose.

Then check the the bleed off screw is very tightly closed. If the threads on the bleed screw get any contamination you will not get a good seal. Light touch of Emory cloth to clean grit.

There is a ball seal that gets residue buildup after several hours of use. It may be dirty from assembly. There is a 19mm (maybe 17mm) brass bolt on the bottom of the unit. Remove that bolt, pull out the plunger ball and spring. Make sure rubber ball is clean. Reassemble.

If you have to go beyond those three easy checks, please post up. Let us know what you find.
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TY- I checked the bleed valve and burst disc and both are fine. I do not have any brass bolt on the bottom of my unit. After doing the two valve check same result. bounce on 220 and the needle gauges do not stop pump.
 
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CfiDave said:
Brass bolt is on top of the compressor. It takes a 19mm socket. After removal you will see the spring and ball. Make sure they are not dirty or full of grease.
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Hi, Maybe I am blind but I don't see any brass 19mm anywhere on the unit. I took off the cover as well and nothing. Could someone post a picture? Going to do a soap-water test but still not happy that I have to go through this with a brand-new pump. I emailed GX since I purchased the pump from them.
 
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Hi, Update- The leak is coming from this fitting in the picture. The air is coming from the block with the burst valve to the round one where my finger is. The bolt seems to be on very tight. Thoughts?

Leak.jpg
 
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FLgunner said:
I recently obtained a GX CS4 compressor direct from GX Pumps. They shipped quickly and it arrived a couple days later, well packaged and in good condition. It came with an assortment of tools, seals, rings, o-rings and springs, so looks like it has the parts needed for a complete rebuild, if needed. Based on other comments here, I flushed the cooling system with distilled water, drained it and refilled with a 50/50 pre-mix of Dexcool anti-freeze.

I ran a quick pressure test and was quite impressed with the speed at which it reached 400 BAR/5800 PSI! It's also very quiet, in fact, it's the quietest compressor I've ever owned and I've had quite a few over the years! Here's a quick video of the pressure test so you can here it running and see how fast it reached it's max capacity:


This is a 4 stage compressor running at a fairly low RPM, yet it makes nearly 10 BAR of pressure per stroke!

After ensuring everything was operating correctly, I filled my LSC SK-19's 580cc tank from 150 BAR to 250 BAR. This fill only took about a minute and the temerature of the compressor barely rose 4 degrees!

I did add a temperature Gauge, not that it's needed with how cool this compressor runs, but I just like seeing what's happening when filling!

View attachment 341675

Here are some pictures of what's under the hood:

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This is the 4 stage compression chamber with cooling fins covering the entire outer cylinder.

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This is the 350X motor driving this beast and providing cooling air to the radiator.

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The auto shutoff pressure gauge is really top notch! Much nicer than what comes on most lower end Chinese compressors. It has 2 set needles, I'm assuming one is a back-up in case thefirst doesn't work. I set it at 400 BAR. The second I set at my desired fill capacity. I will say I have found the gauge to be very accurate, much more so that most of the compressors I have owned.

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This is the resivoir for the cooling system. The whole self-contained system hold about 1 liter of water/coolant.

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Here's another angle of the radiator.

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Here is the burst disk and grease pot, both these are accessible with the cover on the compressor.

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The intake filts elbow was swing loose when I first opened it up, so I snugged it down so it wasn't loose. I'm not sure what the white part is attached to the head, but think it might be a temperature sensor.

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Here is the main controller board.

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When you remove the top of the grease pot, you can see the grease inside. The manual says to turn the knob on the top of the grease pot one full turn every 4-6 hours of operation. I need to contact GX and ask what type of greese to use, just to have some on hand if needed down the road.

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The rest of the grease inside the grease pot.

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This is how it looks with the cover on it, you can see the knob has arrows showing the direction to turn it when needed.

GX Claims this compressor has a 5 hour run cycle and is rated to fill up to a 6.8L air tank! Seeing that the temperature gauge barely moved when topping off the 580cc tank on the SK-19, I have no doubt that heat is not a huge problem with this compressor!

Amazon is selling these for $699.99 plus tax, but buying direct from GX Pumps, you can save over $100! They are currently on sale for $659.99, but by using the coupon code [GXPUMPS10OFF] it brings it to $593.99 shipped.

Thus far I am really quite impressed with the feature of this compressor for it's price point! It seems very solid and built to last. If interested, check out what they offer direct, they seem to alway have several different models in stock and on sale!

gxpumpofficial.com

GX Pump PCP Air Compressor | GX CS4 Air Gun Compressors 2023

GX CS4 Portable PCP Air Compressor, 350W Powerful Motor,Max 5800Psi/40Mpa, Water and Fans Cooling, 5 Hours Continous Work, 12V Auto Stop，for PCP Air Rifle Paintball
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If you have any questions, please post them below and I'll try my best to answer them.
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Hi, My unit does not have the fins like yours where you mounted the temp probe. Mine has a solid smooth cylinder.

Cyl.jpg
 
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Hi All, Here is a picture of my needle gauges. One looks like the red covering is not on or is this normal? Also, I got the leak stopped but more concerning is that the auto shut-off does not work. The pump keeps going past BOTH needles. Tested with just the line between 200-300 bar and every time the pump goes right through the settings. I appreciate any help, TIA

needle.jpg
 
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JimNM said:
Make sure the wires from the shut off gauge to the control board are fitted snugly and in good connection. I had a crosman pump arrive with badly crimped wires which caused the shut off gauge to not work.


How did you fix the air leak?
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Curious as well to what it took to fix the leak. Side note I think you will find the support from gx less than stellar.
 
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