Are all oilless PCP pumps on amazon the same?

Agreed, oil-less, waterless, multi-power, high-speed-fan only cooled rectangular box quick-fill compressors are alike. Expected lifetime is 12-18 months with limited rebuild success. Manufacturers support, "discard, buy another," versus, "rebuild/repair." The GX-CS compressor series differs significantly in that lower gearing, slower fill operation reduces compressor-killing heat while grease-injection and water-cooling are available in some models. GX-CS also supports, "repair/rebuild," over, "discard, buy another." WM

Late to the thread, but have to disagree that all of these compressors are the same. For example, GX CS2, 3 & 4 are very different from the ones like CS1.

If of use to someone, I can post photos of the differences.

The ones I refer to as CS1 clones are very common, sold by Tuxing and many others. They have a sort of industrial-looking piston pump that is easily preparable, or one can simply buy the complete cylinder assembly from such as Ali-Express

Depending on one's skills and how much time one wishes to invest, virtually all are repairable, although identifying parts sources can be challenging.

If this appears to be dismissive or critical of other replies, apologies as that is not my intent.

A follow-up, for anyone who doesn't know: the DC (direct current) power supply that is provided for most of these small compressors typically operates in the 12 volt range and around 40 amps maximum output. They are claimed to be self-limiting in terms of current, and so claimed to be self-protecting.

They do have a small "glass fuse" or "Buss-type fuse" on the circuit board, so if one quits working, that's one of the first thngs to check.

Unfortunately, the fuse is soldered in place, rather than using a clip-type fuse socket, so one needs to have some basic skills to replace the fuse. I have soldered a Mini or ATC fuse holder to a number of these power supplies, to allow for easy fuse replacement, outside the case.

I don't recall having a fuse blow when running a compressor, but I have used this kind of power supply (typically sold as "LED Power Supply" for battery charging, powering vehicles during diagnosis, and other tasks.

I had a weak starting battery in our Xterra, which ran down from powering a compressor when power was off at the range. Of course, that would be the day that no one else was at the range, but power came back on. I just pulled the battery and used jumper cables to connect the power supply to the battery, charged the battery enough to start the Xterra and all was good.

Here are two of these power supplies that I have modified to make them easier to use as battery chargers and power supplies for powering vehicles.

The lower one has a "glass type" or "Buss type" fuse holder, white plastic, while the upper has a Mini Fuse holder.

If any of this information is useful to someone, please let me know and we can discuss the best way to communicate.

Here's what a New Warrior, or Benjamin look like, other than for the colors. One can see why I suspected they were like the GX CS4, until I opened one up.

The Yong Heng-type compressor is obvious, and completely different from the CS4. The main difference between the YH compressor inside the New Warrior and Benjamin is the cylinder head, which is much more complicated and sophisticated in the NW and Benjamin.

What is and isn’t exactly the same who knows. I believe one thing for sure though. There are like 50 different companies using the same manufacturer to make their products. Identical . Kind of like po Tate o. VS po TAT o. I believe gx is one of if not the major manufacturer over there. Trust buying gx branded items.