Issues with brand new GX CS4 compressor

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 said:

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.

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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

sobdiver said:

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.

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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 said:

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?

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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

I remember reading a post that someone else had a defective grease pot. I think it was the rubber diaphragm in the bottom of it that was letting grease into the machine while it was pumping. This caused it to become over greased and slow way down. Seems to be what yours is doing from the pics. I think GX sent him a replacement.
I’ve always thought that water trick was super strange. I mean the grease pot puts grease into the cylinder so wouldn’t that water have to go into the cylinder? That seems like a horrible idea.

It may just be your high pressure piston rings. You have these in a bag along with everything you need to change them out. I haven't needed mine yet but have had it apart to remove extra grease last year. Did you actually run water through the cylinder? Was that what GX posted to remove extra grease?

sobdiver said:

Yes, I ran water through the cylinder exactly per their instructions. Some here have thought that was a bad idea, but if I'm potentialy doing a warranty I need to follow their troubleshooting protocol. Maybe it is the rings? But, how much work should I do on a brand new unit. I'm inclined to draw the line at tearing down the cylinder/piston assembly next. Maybe if I've had this thing longer and it finally needed attention it would maked sense to try and tackle. Here's the video GX sent me for cleaning grease that involves flusing with h20:

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I found that the video was posted by the seller on Amazon where I bought one of my GX compressors. Did you boil the ( I'm sure ) distilled water first? The video shows a tea pot and that usually means one thing. Very hot water. It just seems strange to put water into a cylinder that we try to fight to keep dry.

I wasn't criticizing you just trying to understand the problem.

It sounds like you have a gunked up check valve. Cleaning out is the far better option that using water, even though I understand they don't want to have a new user tearing into it, so this is their best shot at clearing it.

I could go long on this post, but the short answer is, it's time for a replacement. It's over the average user pay grade and you should have to deal with this.