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GX CS4 Compressor - Initial Impressions

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Just curious why you disassembled the burst disc assembly? Was there a problem with it? Is it possible something didn't get seated correctly when reassembled? On mine, I just flushed the tank, filled it with coolant and ran a test run to 400 BAR. It got there very quickly. Almost a year later, it's still filling just as fast and the only thing I have done to it is give the grease pot plunger a turn as stated in the manual.

I see a lot of folks doing a lot of things to these compressors right out of the box and wonder why. My philosophy was do the flush, fill with coolant and run it as it came out of the box. That way if there was a problem, I'd know it came that way and it wasn't something I may have caused by doing more than what was needed.

GX Pumps has been very responsive to folks who have had issues, so I would reach out to them before tearing everything apart and possibly voiding the warranty! Their e-mail address is [email protected]. They are back from their holiday, so they should respond pretty quickly. When I e-mail them, they typically respond in the middle of the night, but I have a response the following morning.
 
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FLgunner said:
Just curious why you disassembled the burst disc assembly? Was there a problem with it? Is it possible something didn't get seated correctly when reassembled? On mine, I just flushed the tank, filled it with coolant and ran a test run to 400 BAR. It got there very quickly. Almost a year later, it's still filling just as fast and the only thing I have done to it is give the grease pot plunger a turn as stated in the manual.

I see a lot of folks doing a lot of things to these compressors right out of the box and wonder why. My philosophy was do the flush, fill with coolant and run it as it came out of the box. That way if there was a problem, I'd know it came that way and it wasn't something I may have caused by doing more than what was needed.

GX Pumps has been very responsive to folks who have had issues, so I would reach out to them before tearing everything apart and possibly voiding the warranty! Their e-mail address is [email protected]. They are back from their holiday, so they should respond pretty quickly. When I e-mail them, they typically respond in the middle of the night, but I have a response the following morning.
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My philosophy about initial startup is very similar to yours. I checked the burst disk assembly because it is designed to be taken apart and serviced by the user(for burst disk replacement), does not require removal of the casing, and others have reported issues with dirt in this area. My burst disk assembly did in fact have a significant amount of dirt. I'm confident in my ability to clean and reassemble this element correctly and have tested it for leakage after reassembly so I highly doubt it's the problem. Users are also expected to correctly connect external power supplies, attach hoses, set pressure gauges, and insert test plugs before the first run.

And yes, I'm in the process of contacting gxpump support. I am more than willing to give them a chance to work with me on this, and do not plan on opening the case until they instruct me to. However I do stand by my original post with regard to my out-of-the-box experience which was not exactly what I expected. Hopefully this will get straightened out quickly and I'll be singing the praises of the CS4 soon.
 
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FLgunner said:
Just curious why you disassembled the burst disc assembly? Was there a problem with it? Is it possible something didn't get seated correctly when reassembled? On mine, I just flushed the tank, filled it with coolant and ran a test run to 400 BAR. It got there very quickly. Almost a year later, it's still filling just as fast and the only thing I have done to it is give the grease pot plunger a turn as stated in the manual.

I see a lot of folks doing a lot of things to these compressors right out of the box and wonder why. My philosophy was do the flush, fill with coolant and run it as it came out of the box. That way if there was a problem, I'd know it came that way and it wasn't something I may have caused by doing more than what was needed.

GX Pumps has been very responsive to folks who have had issues, so I would reach out to them before tearing everything apart and possibly voiding the warranty! Their e-mail address is [email protected]. They are back from their holiday, so they should respond pretty quickly. When I e-mail them, they typically respond in the middle of the night, but I have a response the following morning.
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Can you describe how you flush the CS4? Do you suction the water out or just turn the unit upside down to drain it?
 
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Bigtwin69 said:
Can you describe how you flush the CS4? Do you suction the water out or just turn the unit upside down to drain it?
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I filled the reservoir, turned on the pump, let it run for 30 seconds or so, then shut it off, tipped it over into the sink and let it drain (never put the cap back on the reservoir). Made sure the radiator was the highest point in the system.

Also, some have mentioned having to stick something in the bottom of the reservoir to prime the pump. NOT necessary; simply shut off the pump and restart it one or two times. If you pay attention to the clear hose going to the pump, you'll see if it is full of water or has air in it.

After flushing mine more than 10 times with tap water/soapy water/tap water, I took the return line off and blew air into the reservoir to push all the water out of the radiator, then blew air the other direction thru the return line until no more water came out. This resulted in about 250-260 ml of distilled water needed to fill.
 
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Banjo fittings!

As explained in my previous posts, I purchased a CS4 compressor and had some functional problems out-of-the-box that seemed likely related to leakage. I emailed gxpump support and received a prompt response with instructions for the first round of diagnostics. I decided to check the banjo fittings since that's easy to do and has been mentioned in this thread as a source of leakage. One of the banjo fitting brass bolts was very tight, the other one was just snug so I tightened that one. That fixed the leak, and the compressor was able to make 300 bar in 24 seconds with a test plug. Very impressive, and 37% faster than the advertised spec of 300 bar in 38 seconds!

I'm posting my experiences in case they are useful to others who have similar problems. I don't know how common the under-torqued banjo fitting problem is, hopefully it's rare. Anyone considering work on these components should also think carefully about the possibility of voiding their warranty before proceeding without instructions to do so from gxpump. And be careful, the banjo fitting bolts are brass and so would strip more easily that steel if over-torqued...
 
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gunnar said:
Banjo fittings!

As explained in my previous posts, I purchased a CS4 compressor and had some functional problems out-of-the-box that seemed likely related to leakage. I emailed gxpump support and received a prompt response with instructions for the first round of diagnostics. I decided to check the banjo fittings since that's easy to do and has been mentioned in this thread as a source of leakage. One of the banjo fitting brass bolts was very tight, the other one was just snug so I tightened that one. That fixed the leak, and the compressor was able to make 300 bar in 24 seconds with a test plug. Very impressive, and 37% faster than the advertised spec of 300 bar in 38 seconds!

I'm posting my experiences in case they are useful to others who have similar problems. I don't know how common the under-torqued banjo fitting problem is, hopefully it's rare. Anyone considering work on these components should also think carefully about the possibility of voiding their warranty before proceeding without instructions to do so from gxpump. And be careful, the banjo fitting bolts are brass and so would strip more easily that steel if over-torqued...
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Both my banjos were tight from the factory.
 
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Last night while filling my GK1 to 35mpa noticed it was struggling after 300 bar and heard leaking near top back, opened it up this morning and noticed the temp probe I had taped to the head at the banjo fitting was popped lose the brass nut was an easy twist to tighten it back up 14mm wrench about 1/8 of a turn and back tight ran test plug to 350 bar took 31 seconds. All is well love this pump. I have others but this is the only one that does 5800 psi.
 
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MACTEN said:
Never purchased from alibaba.. I thought they were geared for large numbers and slow boat shipping?
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Just an update to I never ordered from Alibaba ... I Ordered a GX CS4-I from Alibaba's GX Pump store, and it's supposed to get here next week.
I'm told they phased out the zerk grease fitting and went back to the grease pot (not sure though as I don't have it yet)
I do plan on doing a comparison between my GX CS4 the the Internal version to see if they differ in performance.
My plan is to just retire the DAVV SCU30 (Yong Heng style compressor that keeps blowing head gaskets) for filling tanks and use the CS4 external power supply to do it.
 
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MACTEN said:
Just an update to I never ordered from Alibaba ... I Ordered a GX CS4-I from Alibaba's GX Pump store, and it's supposed to get here next week.
I'm told they phased out the zerk grease fitting and went back to the grease pot (not sure though as I don't have it yet)
I do plan on doing a comparison between my GX CS4 the the Internal version to see if they differ in performance.
My plan is to just retire the DAVV SCU30 (Yong Heng style compressor that keeps blowing head gaskets) for filling tanks and use the CS4 external power supply to do it.
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Did the CS4 ever have a grease zerk?
 
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I asked the actual maker (Nantong GuangXing Pneumatic Equipment Co. Ltd) about the grease and "could I buy some, or what grease do I need to buy"?
They replied today..."Our machine does not need to add grease after the grease of the oil column is used up. At this time, the internal parts of the machine have been running in".
Make of that what you will. Looks like the pumps don't need a lot of grease (as long as it arrives with some grease actually in it).
So yeah, looks like the Zerk fitting encouraged folks to over-grease the pump.
 
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Grey-Kiwi said:
I asked the actual maker (Nantong GuangXing Pneumatic Equipment Co. Ltd) about the grease and "could I buy some, or what grease do I need to buy"?
They replied today..."Our machine does not need to add grease after the grease of the oil column is used up. At this time, the internal parts of the machine have been running in".
Make of that what you will. Looks like the pumps don't need a lot of grease (as long as it arrives with some grease actually in it).
So yeah, looks like the Zerk fitting encouraged folks to over-grease the pump.
Click to expand...
I believe I read the same thing, once the grease in the cup is used up, there is no need to refill it. I probably will just because it’s there but will only add any IF the compressor starts to pump differently.
 
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Grey-Kiwi said:
I asked the actual maker (Nantong GuangXing Pneumatic Equipment Co. Ltd) about the grease and "could I buy some, or what grease do I need to buy"?
They replied today..."Our machine does not need to add grease after the grease of the oil column is used up. At this time, the internal parts of the machine have been running in".
Make of that what you will. Looks like the pumps don't need a lot of grease (as long as it arrives with some grease actually in it).
So yeah, looks like the Zerk fitting encouraged folks to over-grease the pump.
Click to expand...
I have to say, this seems really counter-intuitive. When in the history of moving metal parts, would we ever stop lubing them? I mean, most of the contact areas are probably actually rubber-to-metal, but the idea of never lubing a piston again just seems wrong to me. I'll do some more digging into this.

I mean, if it was meant to NOT be refilled, why would they recommend a particular type of grease for refills?
 
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I'm guessing that it was never designed to last that many hours so even if you should lube it other parts are likely to fail for reasons other that a lack of lube. If this wasn't the case why didn't they lube correctly during assembly when it easier to do. Then the grease cup can be eliminated saving cost? Rubber to metal moving contacts don't wear in, the rubber wears out.

I'm saying this even as a recent buyer of one.

Here's some of my thoughts failures.

GX CS4

Thought about it, but I'm trying to follow the instructions to a T. When I received my CS4, I tore it down a bit. Took the cylinder off the crankcase housing (trying to see where the grease goes, but couldn't really tell), and took the grease pot out. There was a pretty big air gap in there...
www.airgunnation.com www.airgunnation.com
 
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Grey-Kiwi said:
I asked the actual maker (Nantong GuangXing Pneumatic Equipment Co. Ltd) about the grease and "could I buy some, or what grease do I need to buy"?
They replied today..."Our machine does not need to add grease after the grease of the oil column is used up. At this time, the internal parts of the machine have been running in".
Make of that what you will. Looks like the pumps don't need a lot of grease (as long as it arrives with some grease actually in it).
So yeah, looks like the Zerk fitting encouraged folks to over-grease the pump.
Click to expand...
It’s actually a food based grease. I recently bought a container and it smells like the same stuff as the original. Consistency and even color.
 
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F6Hawk said:
I know you weren't asking me, but this is what I plan to buy in a coupla years when my pot is empty:


Somewhere I read it suggested using NLGI 0 grease, but looking at what's in the pot now, I'm certain it is NLGI 2.
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That's great...I have that already.
I use it sparingly on my CZ457 bolt cam area.
Thanks.
 
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