GX-E-CS4-I PCP Air Compressor, Max 5800Psi,350W Powerful Motor

At first, I was planning on getting one of those many $200'ish pumps readily available on Amazon. Many even look a lot like the $500'ish ones reputable airgun supply companies sell as their entry level "branded" recommendations. Upon further research, I decided to spend more to get significantly better specs and happy that I did. This one lists a MUCH longer run times (like over 5 hours, the others are like 10-15 minutes at a time), so it CAN fill bottles (still skeptical so not likely to be used as such for me). It is also significantly quieter (based on online reviews and videos of the others). Its noise is literally a FRACTION of even my regular air compressor for cars. It doesn't come with a temp gauge, like many of the other cheaper versions, but this one is water cooled - so it probably doesn't have a heat issue (definitely not even getting "warm" from my own uses). I'm not sure if it comes with a water filter (claims to have one internally) so I got a separate filter (from them). Specs are overkill for my intended uses (direct fill of air guns), but my gun has a max fill capacity of 3 bars, and this one actually is capable of going to 4 bars (the cheaper ones are all 3bars). This might have been the only one I've found that is specced to 4 bars at this price point. Works exceptionally well, doesn't rattle like its overworking itself, is quiet enough to use in the house, and appears to have a good build quality. I think the cheaper ones may be a good alternative to the hand pumps (some actually costing the same surprisingly), but this one appears to be built to last a bit longer (especially if intended to be used casually like I am). Replacement parts seem to be available (but at this price point, I wouldn't be disappointed to have to replace after several years of use). I did have an issue with the water filter I bought separately (hookup error) and the support was immediate, real time, and helpful (same company), so the company has some credibility as well.

My experience with the GX-E-CS4-I Air Compressor is noted by these items: This unit was purchased and this review is based on my perceived value and the function of the unit. Features of this unit that influenced my purchase was quality construction, ability to fill 1.5-2 L bottles, availability of repair parts and ease of set-up. - Shipment was quick and well packaged. The compressor was in great shape when delivered to my door. - Very easy to set up with the written instructions. Just follow the steps and you're up and running in under 30 minutes. - The only assembly to this compressor was adding a coolant to the tank (I used anti-freeze) and connecting the hose. - I added the GX Pro Grade Filter while setting up the compressor for quality air delivery. This is something you should NOT skip if you are putting air into expensive PCP equipment. -Once I set the cut-off pressure and back-up pressure limit, everything performed without a hitch. I have now officially retired my hand pump and can fill my equipment and bottle without breaking a sweat. I'll update this review after using the compressor through the Summer. UPDATE 7/9/26: After running this compressor for over 3 hours total, I have a couple of numbers to run. Just filled up a 98ci (1.6l ) bottle to 300 bar and it took 42 minutes. For an FX DRS 700mm pcp it filled up to 230 bar in 9 minutes. No issues with the pump, filter or bottle.

Excellent compressor! Has all the bells n whistles. Fast fill time. 68ci tank fill from 0-4500psi in 25 minutes. Have filled many tanks with great times. Can fill for 5 continuous hrs with no down time for large tanks. Big perk is it's extremely quiet! In addition has a grease pot which allows you to turn knob every 4-6 hours to lubricate the pump. Awesome feature! Have owned quite a few cheaper compressors n by far this one is superior. Costly but you get what you pay for. If your on the fence about buying this compressor it's definitely worth the cost. I couldn't be happier! Has good instructions with an itemized parts list which is great for if n when could need repairs. Don't anticipate that for a long time. Very pleased with this purchase! GREAT COMPRESSOR! Also has auto stop setting ability with a back up setting to your setting. Pump does not get anywhere near overheating due to the onboard water tank for great cooling of pump.

Buy from GX Pump via official sources with CONFIDENCE, they will stand behind their products. I have already ordered their new high pressure filter system because I trust them to do the right thing when a need arises. Pump works great had a small problem solved quickly by GX pump with a Control Board replacement. Pump builds pressure well, quiet in operation, slow fill rate does not over heat. I have worked on high pressure air and NITROX systems in and out of military. The number one enemy of compressors pumps longevity is excessive heat. This unit controls heat buildup well. Use this unit within its designed duty cycle and I am sure it will provide a long service life before rebuild. I ordered a pump on 27 March 2025 it arrived and would not run for a very long and shut down. It was tried with many options as per technical support via GX Pump. The unit-built pressure on deadhead tests just would not stay running. The failure mode did mode did not match the symptoms of the trouble shooting steps. This was an out of box failure and GX Pump thru its Amazon Official Sales Point replaced unit very quickly. I knew the reputation of these pumps were of high quality and like all factory-built items a poor example slipped thru. The replacement unit arrived quickly via Amazon 4 April 2025 I unboxed it and ran it. The unit had the same build date on tag as the first unit, still I had high hopes. No joy, same indications. Shutdowns happened running on 110 VAC and on 12 VDC. GX Pump Technical support tracked it down quickly to a Control Board (the only common failure point of both voltage modes.) This only affected one supplier Control Board and GX Pump sourced Control Boards that are another supplier (different design see pictures) and sent them out quickly. GX Pump also posted a video instruction on installation quickly.

I love this pump. clean two stage compression. pump never gets hot or bogged down even at 5800 psi. plenty of power. safe, redundant safety features. easy to read and set pressure gauge. took the cover off to look at the internals, great build quality though out.

nice and quiet vs others I have used. it sounds slow but fills faster than my old spritech which died after 4 years of hard use. the spritech was loud and slow but was way cheaper. sounded like a jet plane taking off. the gx cs4-i is way better liquid cooling is a plus and super quiet vs the spritech. so far its been reliable and fast filling a 36/4500 ci tank to 3000 psi in 14min. 24min to fill 68/4500 ci tank to 4500 psi from 1000psi the spritech choked at around 3800 psi. things i didnt like was i had to flush cooling system as there was junk in it from the start like old scaling not sure what it was but it needed to be flushed. second thing is lack of temp gauge. would be nice to know how hot the liquid is for the cooling system. lastly i dont like the fact that the power cord plugs in the front of the machine. i think it should be in the back. overall its a solid machine and works well

I first bought a cheaper compressor, but it started to fail in the first couple of weeks, so I decided to not mess around with inexpensive ones and got this one; It has been working fine, is quieter and faster than the small inexpensive one.

I purchased this as a backup for a model just below this one. I have about 50 hrs run time on the old one when I blew out a pressure disk. I changed out the disk but had poor performance so I decided to try this new unit. Wow, it is quieter and seems to pump just as well or better. I use this at home, so no need to hook up the transformer like the old unit. Later went back to trouble shooting the old unit and found some seals on my service line and connectors had blown. Replaced seals and now have 2 excellent compressors. So when performance starts to decline, check your service line seals. They will probably be the first thing that fails on this well made compressor.

Molto bene grazie mille

I owe already CS4 model (without -I, this one is CS4-I). Again a very good product that can work in a long session and effortlessly can reach 300 Bar, the pressure I need for my PCP gun. This model produces less noise and has 220 V power supply integrated in the unit, so no external one is needed. You can also connect 12V directly to the unit, the same as for CS4. I am happy with both products.

Wow, this Compressor is awesome, its so easy to set up, (tip: buy some distilled water at the same time, its required for use) Its a solid little unit, i though it was going to be way bigger and heavier than it is. Its so quiet, especially compared to my old Heug Yeug Compressor, which did a great job for 7 years with no hassle. But wanted an all in one upgrade with no buckets of water etc etc. This compressor is quality, customer service from GX has been Awesome as well, I emailed them about a warranty and they replied in less than an hour, and said even outside of the 1 year warranty, we're always happy to help with any issues. It fill my bottle from 200bar to 300 in no time at all and turned off when finished. Its an expensive item but well worth it.

Enfin un compresseur de qualité. C'est le premier qui me permet de charger consécutivement 3 bouteilles de 1l de 0 à 300 bars sans pb. Je vous le recommande pour plongée. La séparation de l'eau se fait très bien et je n'ai ni eau ni graisse sur le filtre que j'avais rajouté ! L'eau se purge automatiquement lors du cassage de pression, en fin de gonflage (par le petit tuyau destiné a cet effet). Enfin un compresseur qui tient ses promesses. Pour ma part je l'utilise avec du liquide de refroidissement de voiture (qui contient de l'antirouille) car j'avais utilisé de l'eau distillée sur un précédent modèle et il y avait eu un encrassement et de la rouille sur le bouchon. Et la dissipation thermique se fait sans pb. En plus il n'est pas très brillant. Vraiment il vaut son prix. 1 an après, je suis toujours extrêmement satisfait de ce modèle. Il faut bien noter le nombre d'heure d'utilisation pour ne pas risquer de sur graisser la machine. Vraiment content.

Deze compressor is voor een compressor van dit formaat zeer stil en je kunt gewoon je gesprek met voortzetten als er natuurlijk iemand bij je is wanneer je het geweer gaat vullen. Deze compressor gebruik ik om mijn 6.8liter fles te toppen elke keer van ongeveer 200bar naar 330bar en daar heeft deze compressor totaal geen moeite mee en ik heb 2 extra temperatuurmeters opgezet en wel op beide leidingen van de koeling om gewoon zeker te zijn dat te temperatuur goed blijft en de temperatuur van de koeling komt niet boven de 40graden tijdens het vullen van de fles. Dit is echt een zeer fijne compressor. Een belangrijke tip voor alle gebruikers, gebruik wel een extra filter en plaats deze dan Vertikaal want dat kleine filterunit wat er standaard bij zit is niet voldoende.