The Grease cup on the GX CS4 is crap.......

I just read that article....Thanks for posting that.
The real problem with this grease pot is that rubber in the bottom that is supposed to be the grease limiter...it has a very tiny hole in the center of it that is supposed to let the grease through when turning the knob...but, it appears to me that the grease it's self softens that rubber disc and it deforms to where the hole in the bottom of the rubber no longer lines up with the hole in the bottom of the grease chamber where the grease is supposed to go...so, when you turn the knob you will get to the point where the grease is just compressing against the bottom of the chamber and you can longer turn the knob any further and no grease gets into the compressor. Tomorrow I'm going to take that grease pot back out and take some measurements and I'll machine a thin aluminum disc with the same size small hole as the rubber disc and install it and that should fix the problem.....
Make me one too.. Just say how much. Grass
 
I know this initial posting goes back to Aug 2023 and I have not read every post word for word but someone asked how much grease was supposed to be injected at the specified interval.
Since there doesn’t seam to be a volume of grease specified per se in the manual it is easy enough to figure out.

The formula is the standard volume for a cylinder, pi x radius squared x length of cylinder. The pot diameter (where the grease is) divided by 2 will give the radius of course. A little harder thing to determine the length of the cylinder. The length of the cylinder in this case would be the pitch of the thread on the cup. Determining the pitch can be determined by laying a metric screw with known thread pitch (fairly certain the machine is totally metric) so threads mesh with pot threads. In the machine shop world we use thread pitch gauges but not everyone has a set in their tool box. You can also take the pot to Lowe’s or Home Depot and go to their metric hardware section and lay different screws in pot threads till you find the one that meshes just right. Metric thread example- M8x1.25.
The 8 is outside diameter and 1.25 is the pitch of the thread. The pitch is how far the screw will advance with one 360° rotation. For you, that will be the length of the cylinder in this excercise. The 1.25 is millimeters. Obviously all numbers used in the equation should be metric.
Once you do the math your answer will be in CC’s. It will most likely be a small number, I’m thinking less than 1 CC.
Now that’s if your greasing pot turns one whole revolution. If your pot is supposed to turn a half turn, divide your answer by 2, if it’s 1/4 of a turn divide by 4. I don’t remember what the rotation was on my Omega Air Charger.
Anyway, that’s how to determine volume if you were thinking of injecting with a hypodermic or similar.
Reading the problems with the poor choice of material that GX and others use for the diaphragm, and if I still had my Omega I would make a metal one or do a complete re design of the greasing. I’d be sceptical of a zerk because a grease gun is anything but accurate.
 
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I know this initial posting goes back to Aug 2023 and I have not read every post word for word but someone asked how much grease was supposed to be injected at the specified interval.
Since there doesn’t seam to be a volume of grease specified per se in the manual it is easy enough to figure out.

The formula is the standard volume for a cylinder, pi x radius squared x length of cylinder. The pot diameter (where the grease is) divided by 2 will give the radius of course. A little harder thing to determine the length of the cylinder. The length of the cylinder in this case would be the pitch of the thread on the cup. Determining the pitch can be determined by laying a metric screw with known thread pitch (fairly certain the machine is totally metric) so threads mesh with pot threads. In the machine shop world we use thread pitch gauges but not everyone has a set in their tool box. You can also take the pot to Lowe’s or Home Depot and go to their metric hardware section and lay different screws in pot threads till you find the one that meshes just right. Metric thread example- M8x1.25.
The 8 is outside diameter and 1.25 is the pitch of the thread. The pitch is how far the screw will advance with one 360° rotation. For you, that will be the length of the cylinder in this excercise. The 1.25 is millimeters. Obviously all numbers used in the equation should be metric.
Once you do the math your answer will be in CC’s. It will most likely be a small number, I’m thinking less than 1 CC.
Now that’s if your greasing pot turns one whole revolution. If your pot is supposed to turn a half turn, divide your answer by 2, if it’s 1/4 of a turn divide by 4. I don’t remember what the rotation was on my Omega Air Charger.
Anyway, that’s how to determine volume if you were thinking of injecting with a hypodermic or similar.
Reading the problems with the poor choice of material that GX and others use for the diaphragm, and if I still had my Omega I would make a metal one or do a complete re design of the greasing. I’d be sceptical of a zerk because a grease gun is anything but accurate.
I just ordered this grease since it was recommended at this site.

However, I still haven't come close to reaching the 4-6 hours usage range, but my grease pot was nearly empty when I checked it because turning the knob had absolutely NO pressure/resistance. The plastic "flow limiter" was wadded up when I finally looked at about 1 hour of usage and there was very little grease in the pot. Have had no problems and nearing 2 hours, but from what I have read and from my own experience, without a limiting factor, the pump WILL suck all of the grease from the grease pot in a short time. So, even the aluminum limiter made by another member on AGN which looks to me to have a hole that is too large, it will suck more grease than needed. Sorry, I forget the name and post. I have thought about using tire inner-tube material and using the bottom of the grease pot screw in as the diameter. Then simply poke a small hole in that. The original hole was about the size of a pin used in sewing.

It is obvious that the pump WILL suck all available grease (especially if it becomes liquid/more or less) into the system. My pump ON times never run more than about 3 minutes as I only fill/top-off my guns. This doesn't include the cooling fan run times, only the time the pump is operating.

Oh well, I was going to edit above, but I can't breath... so I hope you will pardon me.

All my best!

Kerry
 
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I just ordered this grease since it was recommended at this site.

However, I still haven't come close to reaching the 4-6 hours usage range, but my grease pot was nearly empty when I checked it because turning the knob had absolutely NO pressure/resistance. The plastic "flow limiter" was wadded up when I finally looked at about 1 hour of usage and there was very little grease in the pot. Have had no problems and nearing 2 hours, but from what I have read and from my own experience, without a limiting factor, the pump WILL suck all of the grease from the grease pot in a short time. So, even the aluminum limiter made by another member on AGN which looks to me to have a hole that is too large, it will suck more grease than needed. Sorry, I forget the name and post. I have thought about using tire inner-tube material and using the bottom of the grease pot screw in as the diameter. Then simply poke a small hole in that. The original hole was about the size of a pin used in sewing.

It is obvious that the pump WILL suck all available grease (especially if it becomes liquid/more or less) into the system. My pump ON times never run more than about 3 minutes as I only fill/top-off my guns. This doesn't include the cooling fan run times, only the time the pump is operating.

Oh well, I was going to edit above, but I can't breath... so I hope you will pardon me.

All my best!

Kerry
Interesting that the pump continues sucking grease while pumping.
 
Does anyone know if there is a internal design diagram of this particular pump? I would be curious to know if it has 2 pistons, a little one and a larger one under that. And how grease is suppose to get to the lower larger piston if the applicator is located at the top of the smaller piston? Wouldn't this just be greasing the upper piston only? And I seem to understand the "suck" effect described earlier, but if that was the case wouldn't the pump "self grease" itself without us having to turn a screw? And people speak of adding grease until hearing a change in pump sound. Does this mean they added enough grease or too much? And I totally agree with the above poster when he stated a zerk is poor design. How could they even think that each end user would be using the same grease gun with the same application per pump or stroke? Saying that, maybe there is merit to adding grease until you physically hear a change in pump sound. Maybe that's when you know the pump has "enough" grease? I really love mine and want to understand all this better so I can keep it running in good order for a long time.

Thx
Ray
 
Bill, at Target Forge.com has the proper grease for your CS4.
He may still be in China at the factory.
He has all the parts too.
Check him out.
I am aware of Target Forge and refuse to pay his outrageous prices. Plain and simple.

He does some nice videos, but his prices are insane for sane people.

All my best!

Kerry
 
Make me one too.. Just say how much. Grass
I have been using the aluminum disc that I machined in mine with no problems, I have like 16 hrs on my compressor now. I'm not making any more of the discs as I don't want any liability if something would happen to someone's compressor using one. In my opinion, I think it's just as well to run one without the rubber gasket or a disc. The grease I use in mine is from Renewable Lubricants, it comes in a 14 oz. tube for 34.00....It's been running fine with it and I believe that much grease will outlast the compressor....:)

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It can only suck grease while the pump is pumping. That is how it works.

Open up the grease pot and run the pump and you will see. (smile)

No, it won't damage the pump to do this.

All my best!

Kerry
That’s a no brainer.
Not sure I believe that it’s supposed to ingest grease constantly, but maybe.
 
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Without some kind of one way valve, wouldn't the grease pot be subjected to the pressure of the pump? And doesn't it seem to be counter productive to have to turn a screw to add grease if in fact the pump is "sucking" it into the works on its own while pumping? Also since the grease pot is located at the top of the pump head, how is any grease getting anywhere else? Does it migrate while running or does the top smaller piston the only part that needs grease?
Ray
 
I have been using the aluminum disc that I machined in mine with no problems, I have like 16 hrs on my compressor now. I'm not making any more of the discs as I don't want any liability if something would happen to someone's compressor using one. In my opinion, I think it's just as well to run one without the rubber gasket or a disc. The grease I use in mine is from Renewable Lubricants, it comes in a 14 oz. tube for 34.00....It's been running fine with it and I believe that much grease will outlast the compressor....:)

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View attachment 428532
Although it will work on the crank, (grease pot) this is the grease to be used inside the cylinders if you take the machine apart from what GX customer service told me. Luckily there is a lot of grease in that tube. Too bad the price went up on ebay.
 
That’s a no brainer.
Not sure I believe that it’s supposed to ingest grease constantly, but maybe.
It's not designed to take grease continually. It will of course if the gasket is removed and then that excess grease needs to be removed if it happens. My compressors gasket decided to slip into the cup and allow all the grease to be sucked down onto the crank. I contacted their customer service and was told to remove that excess grease out of there and make sure not to allow it to happen again or it can cause problems.
I had some thin rubber so I used the grease cup as a template and made my own with a tiny hole in it just like the factory one (too bad these aren't available)
The problem is the gasket was so ripped that it wouldn't stop the grease from entering when the pump is running.
How it's supposed to work is there is always some suction happening as the machine runs but the grease is supposed to be limited by that faulty gasket. After every 4 hour cycle, you are supposed to turn the screw one revolution to put some pressure onto the gasket and that tiny hole allowing a small amount of that grease to have enough pressure to make it through the tiny hole.