This is a GX CS 4(non I) replacement piston from GX in CN. They should be the same/interchangeable between the "I" and standard/original GX CS 4 I would think
Last edited:
Upvote 0
GX CS4 grease again...(sorry)!
- Thread starter Grey-Kiwi
- Start date
I would agree that the CS4 piston, is probably identical to a CS4-I piston.
But these 2 pistons do not even remotely look the same to me.
What am I missing?
I do not own a CS4 or a CS4-I, so I am unable to disassemble and examine, but two4spooky's psiton, and F6Hawks piston, do NOT look similar to me.
But these 2 pistons do not even remotely look the same to me.
What am I missing?
I do not own a CS4 or a CS4-I, so I am unable to disassemble and examine, but two4spooky's psiton, and F6Hawks piston, do NOT look similar to me.
Upvote 0
The difference I believe is the connection between the two/three pics you seek. We are seeing the same thing. Just a pic of difference of the driving force(electric motor to drive shaft to piston assembly) IE the connection between the three(motor and gear reduction >connection rod>piston shaft). Clear as mud? Yeah, I feel ya
Last edited:
Upvote 0
My takeaway: we have an affordable(if disposable) alternative to Alkin/Coltri.
This is a complete piston rebuild assembly direct from GX in CN(China) for the GX CS 4. Alibaba or some such, I forget. Not installed as of yet. Geo-political tensions and such are my reasons to have such parts on hand. *YMMV*. I am new to PCP, trying to look ahead and bank accordingly. Take it for what you will
Upvote 0
I use the Renewable Lubricants grease in the previous photo. It is what GX recommends and it's easy to get here. In other countries, I'd take a look at RN website and get the specs, and then contact a local company and see what they can recommend as a replacement. It's not a real heavy duty use, so almost anything would seem to be acceptable, but it seems silicone based is the best path and additional PTFE wouldn't hurt a thing. Remember the PTFE danger is beyond 600F, which your compressor is not likely to ever see and you'd have to be standing there breathing it in (worked with it for years in plastics industry in product development). Dow Corning Molykote 33 would be a good grease, but probably overkill.
Upvote 0
Others here have posted that the grease supplied, doesn't fill the whole grease pot. I reached out to the manufacturer and they agreed, the grease needs to be flush with the bottom of the pot. You may want to check yours and adjust the adjuster in until the grease moves forward enough, then level off the grease. Or better yet, back out the adjuster all the way and re-pack.
Upvote 0
This is a French website but you can use translate it shows the replacement piston for the CS4 and cs4i. Also has a parts diagram on the web page.
Upvote 0
That is MUCH better than the owner's manual diagram, thanks for posting!! Gonna add it to my thread as well.
Upvote 0
This is what I am using:
Although I don't use my GX CS4 as much as many others, I am not worried if this grease is not "good enough".
I have about 3 or 4 hours on it now and it is still running like a Singer. (smile)
All my best!
Kerry
p.s.
If you don't get the reference to Singer, then you are really young. (chuckle)
Although I don't use my GX CS4 as much as many others, I am not worried if this grease is not "good enough".
I have about 3 or 4 hours on it now and it is still running like a Singer. (smile)
All my best!
Kerry
p.s.
If you don't get the reference to Singer, then you are really young. (chuckle)
Upvote 0
I forgot to mention that my GX CS4 came with very little grease in the grease pot. The flimsy "grease limiter" was all folded up and not doing its job. I tried to make it stay flat at the bottom of the grease pot, but as soon as I screwed the cylinder down, that flimsy little POS, simply wadded up again.
So, I made my own flow limiter by cutting out a disc/disk of plastic using the lid of an ice cream or margarine lid. Works just fine!
If you don't use a flow limiter, the GX CS4 will suck the grease pot nearly dry long before it truly needs grease added.
On another thought, thanks to whomever verified that the grease actually DOES enter the compression cylinder from the grease pot. When I tried to claim that, I was told that could not be so. Never made sense to me that the grease was only being "inhaled" to lubricate the cranks axles, etc. (chuckle)
All my best!
Kerry
Upvote 0
You're welcome. Far too many people try to expound on how the CS4 works who have never even opened the cover, let alone taken the cylinder housing apart.
The grease pot ONLY lubes the cylinder, and never touches the crankcase. That has to be done manually.
Upvote 0
I wonder what type of grease silicone or oil bases lubes better, minimizing wear and increasing lifespan of the sealing rings. Since it is said there are 2 sealing rings per piston then in the ideal world there isn't any metal on metal contact of the pistons to bore. Only the sealing rings should wear out if they are replaced before failure.
Upvote 0
Although I don't think the internal temperatures of the CS4 pump "should" cause dieseling, the pressure might, just like in springers. So I would stick with silicone based lubricants. When high pressure and/or heat is involved, you really don't want anything that is combustible for a lubricant.
I will stick with food grade silicone lubricant with a viscosity of NLGI 2. The grease I use has similar viscosity/consistency to what originally came (what little there was) with the GX CS4 when I got it.
To each their own and I don't claim to be an expert. (smile)
All my best!
Kerry
p.s.
See my above post about the grease flow limiter! The one that came with mine was a flimsy joke!
Upvote 0
I have been struggling over trying to find a sound answer for a while now. So many people on AGN use NLGI 2 grease (which seems thicker than the grease from the factory). The manufacturer (I fear mostly due to the language barrier) doesn't specify a grease (I am trying to find out what they put in the pot in the factory), though they have said in several places that the Super Lube NLGI 2 grease is fine (and none i needed after the pot is empty or after a year), but the Omega folks (same factory as GX) seem to recommend the Renewable Lubricants NLGI 0 vegetable-oil-based grease (not synthetic like silicone, but with a lower viscosity).
Silicone grease by its very nature is thick, even thicker than NLGI 2 typically (I use it on o-rings when inspecting SCUBA tanks), but it is recommended for o-rings in general, as it is a great sealant and keeps the rubber supple.
Reminds me of an oil thread on a car forum. It's easier to find a pink unicorn than standardized Foster fittings and the RIGHT grease for the CS4.
I think I need an Old Fashioned...
Last edited:
Upvote 0
I am far from an expert on all this, but I can tell you that the consistency of the grease I use is close, if not a little bit more "liquid" or lower viscosity than what I found in my grease pot when I got my CS4. But it IS NLGI 2 and very close to what I found in the pot originally. Also, since vegetable oil is combustible just like petroleum oil, I would stay away from that for that reason alone.
Not to mention that vegetable oil thickens/oxidizes and gets stiff over time. So I will stick with silicone based grease. It is what is recommended in 99.999999% of the case when it comes to HPA and airguns. Silicone doesn't degrade in such a fashion, AFAIK, and does not combust.
As I said, I am no expert, but I have been reading about this stuff for several years, so I hope I have gleaned the correct info. (grin)
All my best!
Kerry
p.s.
I wish all airguns had a standardized foster fitting instead of a non-standardized fill "probe"! LOL!
All my best!
Kerry
Last edited:
Upvote 0
The Haynes grease is NLGI 2? Tried looking for that info, but couldn't find it yet.
As for the veggie oil stuff... Omega compressors recommends it. They use it in their compressors. No one that I have heard of has had an issue with it.
But I agree, silicone will remain pure for much longer than veggie based oil. Even though GX does NOT recommend it, I know it is recommended just about everywhere rubber or EPDM seals are used.
Upvote 0