How to refill grease pot on GX-CS4 Compressor?

As I recall, Gx advises each user of a CS4 to pay attention to the "speed" at which the compressor operates. My CS4 makes a distinct "thump" on each cycle. Each time I use the compressor, I time the number of thumps - currently 100 thumps per minute - to make sure the compressor is not slowing down. I don't have the pamphlet that came with my compressor handy right now but I believe Gx advises the user to add some grease if the compressor slows down.

JackHughs

Gevtron said:

Thanks Jack. I will keep my ear out for those "thumps". Haven't had a chance to run it yet (waiting for the grease to arrive). Did you already had a chance to inject more grease into the machine? If so, did you time your usage on the machine or just went with the speed degrading method? Appreciate your input. Hope this thread helps someone else with new CS4 since this grease mystery topic seems to be hot topic online.

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I had about 2 hours on my CS4 when I read post warning of large air bubbles in the grease. I then opened the grease cap and found a large air bubble. There was no need to add grease so I just stirred what was there to remove the bubble. With the cap off, I turned the adjustment knob until the grease was flush with the opening and then reinstalled the grease cap. Because of the bubble, it seemed prudent to turn the adjustment adjustment knob in until I felt resistance.

It was then that I started timing the thumps. The compressor has about three hours run time since then. I plan to the knob in one full turn at four hours run time.

JackHughs

Gevtron said:

Oh thanks man! Appreciate it. If I can help in the future with any 3D Printing related stuff for this hobby, you can message me directly.

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Very kind of you, had a feeling you're a decent guy. Plenty members here just like you, sure you'll be a good fit. WM

Gevtron said:

Thanks Jack. I will keep my ear out for those "thumps". Haven't had a chance to run it yet (waiting for the grease to arrive). Did you already had a chance to inject more grease into the machine? If so, did you time your usage on the machine or just went with the speed degrading method? Appreciate your input. Hope this thread helps someone else with new CS4 since this grease mystery topic seems to be hot topic online.

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You can go ahead and use your compressor. It comes greased from the factory. You don’t need to think about turning the grease knob until you have some hours on it. I have been using mine to fill rifles and have never touched the knob. It only takes me 2 to 2-1/2 minutes to fill a rifle. It will be a while before I get to 4 hours worth of run time.

When I owned an Omega Air Charger it had a grease cup for lubrication. When filling the cup, mine unscrewed from the compressor and you invert it and start adding grease to the cup. The biggest issue is entrained air bubbles. To eliminate air bubbles you add a small amount of grease to the cup then tap it briskly onto a table or piece of wood. That action drives the grease down and the air bubbles up. Repeat until cup is to desired fill.
The next issue is priming the grease passage to where grease is getting to where you want it. On the Omega the grease is injected into the air intake just inboard of the air filter and is sucked into the cylinder/s while running (hopefully). I unscrewed the filter so I could see grease coming out the intended hole. That way you know that grease is coming out, not hoping it is. I ALWAYS removed air filter at grease time so I could visually see the grease volume being dispensed. I’m pretty sure all the cheap compressors with grease pots grease in that manner.
I always thought of it as “a good idea, poor execution”. I switched to an Alkin.

Oof. I may have to check on mine. I just turned the smaller knob without checking the larger knob for air pockets. I've racked up about 20 hours in 8 months. However I do fill my small 3L air tanks.

zerochance said:

Oof. I may have to check on mine. I just turned the smaller knob without checking the larger knob for air pockets. I've racked up about 20 hours in 8 months. However I do fill my small 3L air tanks.

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Yeah, you want to make sure that when you turn the knob, it is actually dispensing grease. It’s almost as if a zerk fitting and a grease gun would be better but a grease gun pumps out much more grease than what that little compressor needs.

rcs9250 said:

Yeah, you want to make sure that when you turn the knob, it is actually dispensing grease. It’s almost as if a zerk fitting and a grease gun would be better but a grease gun pumps out much more grease than what that little compressor needs.

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I finally got a chance to look at mine. There was a black rubber piece that was blocking the grease. It wasn't on the outside blocking the grease pot like in the picture but it was in the grease pot blocking the grease. I'm 10 hours over due... but I guess better late then never. After removing the rubber piece and pushing the rest of the grease in, it does seem like it's pumping faster and has less vibration. I then cleaned the grease pot and put new recommended grease in the pot (Renewable Lubricants NLGI-0). Ready and good to go for the next 6 hours. Hopefully the black rubber piece isn't needed...

You need that rubber piece in there. Without it, your compressor will be easily over greased and plug up...requiring a flush of the compressor.

The rubber you have is of the older type and is now oversized. Trim it to fit. There is a tiny hole in the center of the rubber

1900colt said:

You need that rubber piece in there. Without it, your compressor will be easily over greased and plug up...requiring a flush of the compressor.

The rubber you have is of the older type and is now oversized. Trim it to fit. There is a tiny hole in the center of the rubber

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So that tiny hole on the rubber will allow grease to flow when I turn the knob and will also stop the grease from flowing in due to gravity?

zerochance said:

So that tiny hole on the rubber will allow grease to flow when I turn the knob and will also stop the grease from flowing in due to gravity?

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Correct. As the compressor cylinder head warms up, the grease will too and will flow easily. Without that rubber, you'll have a lot of grease going into that compressor very quickly.

The tiny hole is all that it needed, the compressor sucks air/grease from there and through the air filter.

1900colt said:

Correct. As the compressor cylinder head warms up, the grease will too and will flow easily. Without that rubber, you'll have a lot of grease going into that compressor very quickly.

The tiny hole is all that it needed, the compressor sucks air/grease from there and through the air filter.

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That's good to know. Good thing I saved that rubber piece. I cut it to size and put it back in. Thanks for that info.