Issues with brand new GX CS4 compressor

[sobdiver]

Last week I received a GX CS4 compressor ordered directly from the company. Intended use is to refill the 580cc tank on my FX Crown. My first Dead head test after unboxing took 32 seconds to 300 bar. I topped off my Crown and it took about 5 minutes, very happy. Then the pump started having fills and or dead head tests that were VERY slow. Dead head tests to 300 bar started taking over 2 minutes, It was intermittent though, then would go back to 32/33, then back to over 2 minutes. Here's a video I did for GX support that shows a 2 minute plus dead head test, then letting it sit for 5 minutes to show no leaks. (video is Unlisted on Youtube, but can be accessed with the link)

GX support wanted me to try this:

If that didn't work, this:

I followed the instructions in the first video. After removing the check valve, it was all gunked up, so I cleaned. More gunk came out after running compressor for an hour with check valve removed. I never turned the grease knob previously and once again this is a brand new compressor. Cleaned out, reassembled and ran another test. Dead head test took 32 seconds, I was hoping for a better time, so I then did video number 2, removed the grease pot and flushing with water. Here what the grease pot looked like, this must be the air gap I've heard mentioned lol:

after flushing with water, I did 2 or 3 dead head tests and it's now down to about 30 seconds to 300 bar. Way better than 2 minutes, but most dead head results I've seen posted online are a few seconds better. Now I need to wait and test again as previously it usually seemed to do bad after sitting, then get back to GX with the results. If things seem like they are working good now consistently, then need to figure out how to deal with that grease pot. Anyway just wanted to share my experience so far...

 

[bchannell]

I'm missing something here. You did a deadhead of 32 sec but we're hoping for better? You saw times posted a few sec better?

You're chasing your tail. Those times are for reference, not for a record time. There are differences between compressors than will cause a few sec difference, not to mention your compressor is not even broke in yet.
Also, I wouldn't flush the grease with water. I'm not sure what you're trying to accomplish with that.
You seem to have solved your problem, if I understand you. So just use and enjoy.

 

[sobdiver]

I'm missing something here. You did a deadhead of 32 sec but we're hoping for better? You saw times posted a few sec better?

You're chasing your tail. Those times are for reference, not for a record time. There are differences between compressors than will cause a few sec difference, not to mention your compressor is not even broke in yet.
Also, I wouldn't flush the grease with water. I'm not sure what you're trying to accomplish with that.
You seem to have solved your problem, if I understand you. So just use and enjoy.

Yes, I think you might be missing something. My brand new CS4 was intermittingly filling very slow (over 2 minutes dead head test compared to times of 24-28 seconds I’ve seen shared online. GX sent me suggestions of what to try. One of the videos from GX Support showed how to flush the check valve with water. I followed their instructions exactly. It’s not something I came up with on my own. Although initially my dead head test after following their suggestions got closer to the benchmark times I’ve seen others share, it’s not clear if I’m out of the woods. The compressor has already exhibited the behavior of working ok temporarily, followed by not working again after sitting.

 

[JackHughs]

Yes, I think you might be missing something. My brand new CS4 was intermittingly filling very slow (over 2 minutes dead head test compared to times of 24-28 seconds I’ve seen shared online. GX sent me suggestions of what to try. One of the videos from GX Support showed how to flush the check valve with water. I followed their instructions exactly. It’s not something I came up with on my own. Although initially my dead head test after following their suggestions got closer to the benchmark times I’ve seen others share, it’s not clear if I’m out of the woods. The compressor has already exhibited the behavior of working ok temporarily, followed by not working again after sitting.

This may help. Always turn your compressor on with the the bleed valve open. And, always turn the compressor off by first opening the bleed valve. Then allow the compressor to run for 30 seconds or so under no load before turning it off.

In my opinion, this procedure helps to "blow out" all the grease in the internal high pressure lines. It works for me.

JackHughs

 

[BriarpatchMtn]

Yes, I think you might be missing something. My brand new CS4 was intermittingly filling very slow (over 2 minutes dead head test compared to times of 24-28 seconds I’ve seen shared online. GX sent me suggestions of what to try. One of the videos from GX Support showed how to flush the check valve with water. I followed their instructions exactly. It’s not something I came up with on my own. Although initially my dead head test after following their suggestions got closer to the benchmark times I’ve seen others share, it’s not clear if I’m out of the woods. The compressor has already exhibited the behavior of working ok temporarily, followed by not working again after sitting.

I'm certainly not an expert or know all on the GX4 compressors, far more knowledgeable people on the forums than me.
Have had mine 18 months and just hit 100hrs. I've read everything on here I can about them, satisfactions, disappointments, mods, ect. And still reading.
My understanding is that the factory assembles with enough grease already in them for the initial break in time. Yours possible got to much during assembly, it happens, thus the GX videos. Hopefully they've remedied your problem and you can get as much use from yours as I have mine.
I didn't understand the grease pot air gap either, so filled the entire pot myself then turned knob till felt pressure against the diaphragm. Before I hit 10hrs mine was running hot. Checking everything I found my diaphragm had split slightly and nearly the entire pot of grease I'd just filled got pulled into the cylinder. Had to flush it as you've done. Which did get things back to normal.
These compressors really don't need much grease, too much causes multiple issues. I gather that they actually pull small amounts of grease in on their own as they run. I believe that the intention of the air gap is to prevent that during the initial break in since they supposedly already have enough from assembly for that. Then the 2 turns to get grease in contact with the diaphragm and a tad in cylinder.
Since clearing mine I've maybe given it 2 to 3 full turns. I'll check the dead head every 10hrs-ish if it's slowing I'll give it a 1/4 turn then check again after a little run time to see if it improved. But if it's not obviously slowing more than 5+seconds (got to account for imprecise pressure settings and reaction time with watch) I'll hold off greasing. It's really not about counting every single second, it's more of noticing any obvious changes in performance. This routine has kept me within 3 seconds of my out of the box dead head.
I'm not saying this is the correct way, or the best way, it's simply what I've done while crossing my fingers that I doing it right.
Will be pulling my cylinder this weekend for a PM check, hoping to get another 100+hrs out of it.

 

[sobdiver]

This may help. Always turn your compressor on with the the bleed valve open. And, always turn the compressor off by first opening the bleed valve. Then allow the compressor to run for 30 seconds or so under no load before turning it off.

In my opinion, this procedure helps to "blow out" all the grease in the internal high pressure lines. It works for me.

JackHughs

So, are you saying to not use the auto shutoff feature, to watch the needle and open the bleed valve when you get to your desired pressure?

 

[JackHughs]

So, are you saying to not use the auto shutoff feature, to watch the needle and open the bleed valve when you get to your desired pressure?

Yes. I only fill tanks - no one way valves. I monitor tank pressure, turn off the tank valve, and then open the bleed screw on the compressor. I don't use auto shut-off because I don't want the compressor to stop under load.

JackHughs