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Yong Heng Review...AND MORE!


May 21, 2020
    Now that I have had it for a few months I thought I would submit my product review. Spoiler Alert,
    I like it.

    First of all, before buying a Yong Heng I watched every video on YouTube I could find and read all the comments for every video. As a bonus here I have included those comments below this review as there are many helpful hints for operation and maintenance.

    I bought the simple version of this compressor as I am either poor or cheap depending on how you look at it. It came when they said it would and was packed well. I decided to place mine in the upstairs bathroom because I could use the bathtub for the cooling bucket, and because I live in Florida and it is humid down here right around now. No need to pump that moisture into my guns.

    I started out with using a 5 gallon bucket for the water reservoir, but quickly changed to a one gallon, modified milk jug. All I fill are my rifles. The compressor is never on for more than a few minutes and never gets hot enough to require a metric ton of water. In some YouTubes guys went out and got new, more powerful water pumps, but the stock one works well enough for me. The output nipple did bust off (rather easily) and I had to epoxy it back on. I made sure to apply some synthetic lube to both ends of the cooling tubes after that. My model has no electrical sockets, which to me is a good thing, so the water pump goes into the extension cord.
    Oil? I didn’t go nuts. Home Depot had some synthetic stuff for a couple bucks and I used it. In fact, I just did my first oil change this week. I had about an hour and a half on the unit and figured it would be a good time to drain out the break in debis. The oil was a bit gray. I let it drain for about 30 minutes and then poured a little clean oil in to help flush out the crankcase.

    I blew one burst disk somehow—don’t remember. It was easy enough to replace. They provide 5 extras and a bunch of extra 0 Rings, too. They also provide 5 extra air filters, too. Some owners have went out and picked up expensive filter systems for their set up. I did not. The one they provide works well enough. I check it regularly and have never had one soil all the way through so far—I am on number 2. I expected the first one to go pretty quickly due to breaking in the unit, but it did not. BTW, replacement filter packs are available cheap.

    Somehow, one day a few weeks ago I managed to blow out the small 0-Ring in the Foster Fitting. The thing wouldn’t fill my gun after that. With a little help from some fellow airgunners, I got that figured out and bing bang boom my guns are filling again. Disaster averted.

    It is loud, but all compressors are so I can’t complain about that. I do wish the filler hose were l o n g e r. I constructed a little table rack out of PVC to hold the compressor and provide a means to hold the rifles during filling. So far it has worked out very well. It does make some stink, also. Not a lot, but not a little either. The smell does seem to dissipate fast though. I got a cheap Fahrenheit thermometer to replace the Celsius one the unit comes with. It is just easier on my brain. When I fill a single rifle it normally only gets to about to 90 or so degrees. The temperature of the compressor continues to climb even after the unit is turned off and does so for a few minutes. So, keep an eye on that.
    All in all, at this point, I have to say I am satisfied with my purchase. If I get 300 fills out of it that would be my minimal basic output expectation. Everything after that would be gravy. Don’t know why I picked that number for sure. Sounds good.


    Thomas Beauchamp
    1 year ago
    If you keep the black filter and hose higher than the pumps discharge the moisture will flow back into the the aluminum block so it can be blown off with the bleed off knob, and should be done on the high and low side about every five minutes while filling. Keep the tampon prefilter changed when it shows saturation through to the back side so nothing goes to your gun or tank. I use a second filter filled with molecular sieve above the tampon filter to remove any additional moisture. You can also add a layer of carbon below the sieve if the smell bothers you but it won't damage the gun. The sieve I use has color changing beads so it's easy to tell when it needs replaced. I refill my 45 minute scba tank from 3000 psi to 4300 psi in about 15 minutes and my temp is just reaching 60C when I turn it off.

    Lone WOLF
    Lone WOLF
    1 year ago
    Just thought I would add something on this, Your Yong Heng can get up to 75 C that is max temp so try to keep under that, if it gets to around 65 C open bleed valve on rt side & allow any water to escape before shutting off. Also it would be good to have your air line running up on a post to keep water in filters instead of laying air line to lay flat. I added a extra filter with Dry Dry Beads & removed the filters, ( this will keep more of the water out of your gun) Using running water in a bucket works well to help keep temp down, Mine avg around 56 C this way. Hope this helps, If anyone has a Facebook account please look up group ( PCP Compressors,& tanks The good bad & ugly) There is a lot of guys that can help give any advice. also we have a guy that sells parts for the Yong Heng.

    This unit has been out for a while, most reviews give a positive response, when you are working with 4500 PSI you can expect some blow by of oil, the real culprit is moisture , if you can put the compressor in a controlled low humidity room it will help eliminate some of that, your idea on a larger filter intake is a good idea !

    Oil coming out of the bleed valve is normal. Idk why you are overreacting and thinking there is a problem or the case is leaking. Oil and moisture will build up from all the pressure. And when you bleed. It comes out. That is why we all use a oil/water separator at output so all the junk wont go into our guns. Even high end compressor costing $1000 to $2000 will have oil and moisture when you bleed too. Perfectly normal and not dude to cheap Chinese junk.

    I had some oil get into the air gun when I first started my pump. It took some time for things to wear in. I run it no more than ten minuets at a time allowing the water pump to run continuously. Purging the water and dirt is important.
    Did i mention how much of a god send this thing is?

    Very good vid. Ran super cool with out ice. I painted cars. Home. Added a big filter for oil and water. Held a tolit paper size roll. Before painting no air on. I moved a lever on filter to open and any water or oil drained down on floor. Same as the valve on the left. Not air line side. That side should be opened first then the air side next. I had to replace filter every 5 or six times. You will get water and oil on the left side. Never open at at bottle. I just bought one of these. If you open the air line side first you will have more gunk left. Open left side as you look at it from front. Oil water blasted out that side

    check the nuts and bolts periodically for tightness. dry out/wash filters,,reusable. pads for the compressor legs. silicone caulk around the fan housing.

    ood tips, I run it with distilled water and a water wetter for cooling, also Amsoil has a excellent synthetic compressor oil. On first oil change pop off crank cover and trim gasket so it gets full oil drain and wear particle removal. Open it up, not hard, you will see the issue with gasket not allowing full drainage.

    Chris LX200
    Chris LX200
    1 month ago
    If the end of the return tube is below the water level in the bucket (as opposed to above the water surface and just pouring into the bucket) then it doesn't matter if the bucket is a long way below the height of the compressor! It's then a closed system and the weight of water in the return tube is equal to the weight of water being pushed up into the feed tube. Works by gravity - basic science.

    Very nice review on that monocular sieve tube , that will keep your fill station air dry and your pcp airguns free of moisture and oil , my yong heng compressor has a moisture beading valve on the left side and the main pressure bleed valve on right , when filling your tank you can blead moisture as your compressor is running every 3 minutes , AWESOME VIDEO'S

    I have posted the tree stand setup take a look at the next compressor video. No need to place one on the inlet because there is not enough pressure to make the filter works. It has to just be on the high pressure side. What does work is keeping a humidifier set on 40% in you basement and doing all you filling there. Sometime the humidity can get as high a 80 or 90 percent in the garage or outside. Thanks for watching.

    ROBO K
    ROBO K
    5 months ago
    filled mine with rice in the centre and sponges either side I’ve been doing it like this for 2 years now with no issues and have just got my dive bottle back from the testing factory with no issues it’s cheaper and works really well great video keep them coming 👌

    Yes, still using aw#46 hydraulic oil. Some good me about another oil that does not smell as bad as aw46.

    Great video as allways. I have just one little addition about the oil to be used. Using the recommended AW 46 hydraulic oil is perfectly fine and seems to be working out great for most people when only filling your gun for half a minute to a minute but even then and definatly when filling a larger tank I strongly recommend a purpose made synthetic HPA compressor oil that can cope with the 200 degree Celcius (400 Freedomheit) that the airtemperature can reach in te second stage without carbonizing and causing a carbon buildup that will cause failure in tha second stage in time. The rest of the compressor will run just fine with just about any non-detergent oil.

    Thanks for all the information on this compressor which I bought a year or so ago after watching your review. I would add that while aluminum doesn't rust, it does oxidize just like iron and every other metal, especially in contact with a dissimilar metal in the presence of water (an electrolyte), which is why we have dielectric unions and sacrificial anodes, it's called galvanic corrosion. Aluminum does tend to self seal by forming an oxidized surface layer, but that is tenuous at best, especially in contact with dissimilar metals and water.

    Next week will mark the 1-year-anniversary of My Yong Heng compressor..
    It's working just as nicely now as it did the first time I fired it up and put it to torture, I mean use..
    Last year, when I got mine, I also got a new 9L / 95CF carbon fiber tank, so I had to fill from 0-to-300 bar.
    Since then, I've also had to do a 0-to-200ish bar fill on a larger aluminium scba tank. Flawless both times.
    To limit any moisture, overheating, excessive wear issues, I limited the run-times to 10-15 minutes..
    Royal Purple hydraulic oil is used, and I throw a 2ltr bottle of frozen water in w/ the 5gal bucket of water for cooling..
    Aside from that, all OEM accessories were used. [I still haven't hooked up my custom dryer/separator setup yet]
    Those two tanks and occasions were the only times when I had to do such large capacity fills..
    Normally, they just get topped off to their max pressures, and, I'll periodically use the YH to direct fill rifles..
    I have the auto-cutoff-version, and though I've tested it a few times, I don't rely on that function..
    I purge air manually and I start / stop the compressor manually - Better to be safe than sorry.
    **Hard stops aka Turning off the comp w/ the on/off switch WithOut purging the air.. [I've also never done that]
    There were a few reports of 'broken YH comps', and further inspections showed that for some reason,
    the build up of high pressure in the top / high pressure head would slam down when the motor stopped,
    and the force would push the hp piston down onto the top of the low pressure piston hard enough that
    it would dent and/or break through the low pressure piston.. So most people recommended purging before shutdowns
    just in case. Since then though, they've re-engineered the components, so, that should be a thing of the past..
    There were a few different revisions of the Authentic YH compressors, so as long as people are getting the real deal,
    they'll be good to go.

    o8k o8k
    o8k o8k
    2 months ago
    great video. Learned a little bit. I use an omega supercharger myself. the prospect of a replacement for 300$ is intriguing, though lots of add-ons just make it work correctly appear necessary to me. 7:45 Galvanic ionization and/or simple water corrosion (any two dissimilar metals immersed in an electrolyte is a battery). Distilled water( removes the electrolyte component) with an ethylene or propylene glycol additive (helps prevent water from becoming an electrolyte again) will reduced this corrosion considerably. simple water cooling rig for a desktop PC might do the trick.

    5 months ago (edited)
    On air conditioning pumps they put filter-dryers on the suction side of the pump instead of the output side. Maybe it would be a good idea to use a filter on the input suction side and on the output high pressure side. That might help to keep some dirt out of the compressor and help the piston rings to last longer.

    Quick question used my yon heng 3 times now it wont pressurize past 900 to 1000 psi any ideas?
    Air Velocity Sport
    Air Velocity Sport
    5 months ago
    Somewhere you have leak. I would try to run it till it gets to Max pressure then shut off and quickly listen for the leak. If that doesn't work then try using soapy water on connections while running. Remember to completely and thoroughly clean the compressor. Can be corrosive.

    Heath Halfhill
    7 months ago
    Thanks Aaron. I have also have a Yong Heng and i fill a 68 cubic inch and a 3 liter carbon bottles to 4500 psi and have been doing it for over a year with no problems either. I did get a 80 GPM pump for 9$ on Amazon and still have the original pump for back up. I use Royal purple Synthetic oil which is without question a major part of the reason this pump hasn't had any issues but with that I also use a powerful compact fan to keep not only the pipes cool but also the cylinder heads. I use a very small cooler, holds about 8 soda cans, filled with ice...a 7lb bag of pure water ice...and a little bit of water, enough to cover the pump.I also got rid of the thermometer that reads in celsius because i don't understand it and replaced it with a twin pack of the exact same ones that reads in fahrenheit for 5 dollars also on Amazon. My compressor, using this system, has never gotten over 97 degrees ferinhight.
    I also use my compressor on a roll out yoga mat...2$ at a yard sale, made of heavy foam to reduce noise and vibration. My compressor fills these two bottles 3-4 times a week plus a 22 cubic inch bottle on the Gauntlet and several 480cc carbon bottles on the FXs and the LCS SK-19. These compressors are amazing and just because they are made in China, people sometimes think that they are cheaply made and they wouldn't waste their money on them. Brother...they are wrong. I have removed the motor and all metal and at all contact points where a screw would be or metal to metal contact, adhered double sided sticky foam tape to stop any metal vibration and noise that my be made by it. The sound of my compressor after doing this vibration deadening with the foam tape has made a big difference in the overall tone and loudness of this awesome little machine. The grill for the fan motor also did vibrate a bit and was fixed easily wit clear silicone window sealer in a caulking tube.
    Ice, fan, higher flow water pump, a temperature gauge i can understand in fahrenheit, sound and vibration deadening materials, and most importantly synthetic compressor oil preferably Royal Purple. Simply, cheap, effective, and a whole lot quieter and cooler. I'm going to try your soaking wet socks and see if my temperature gauge reads any difference. It all helps in the end. Thanks for sharing and helping the newbies. Hopefully your viewers will watch and learn how to make their compressors last like us. I didn't buy the molecular sieve that you have in the video but did make a couple for around 50 dollars with the help of Stephens video at Air Velocity Sport on this compressor. All the components where purchased on Amazon and eBay and have lots and lots of the moisture gathering material left over. It is reusable, 1 of them is Molecular sieve beads type 13x and the other is silica gel beads that change color when they need to be change and recharged, plus activated charcoal. Together they remove water, oil smoke and the smell of it. I don't know if you can breath it, not that I would,but the guns i hope appreciate it. Thanks to guy's like you ,Southern Gunner , Stephen at Air Velocity Sport, Hajimoto and so many others for helping the new air gunners enjoy this sport without the sometimes expensive learning curve. Thank you for your knowledge and the time you take to share it. Hopefully something I have done with mine can be added to others as well as the wet socks. I am going to try it and watch the gauge to see if my compressor will get any cooler. Thank you


      If you replace the air intake sintered brass "muffler" (intake air filter) with an actual air filter it will be much quieter to the ear. I want to say it drops at least ~5-8 dB and you get the added value of filtering the input air to avoid cylinder scoring or premature O-Ring wear. All my LPA compressors including my 1ga framing nailer compressor have an air filter. Hope this helps!
      The Simple version does not have the cyclone water/oil separator that the other three versions have so it is pumping a considerable amount of water and oil out into your filters, guns and tanks. I expect you have already noticed. In the end it is less expensive to purchase the Hardcopy or Set pressure units with the water/oil separator as you will not be constantly replacing your filters. I left out the Autostop version as it auto stops at around 3000psi so not useful to many of us.

      It's good that that it is still werqing for you though and that you have made your own filter that can be dried out and used again that keeps the cost down for sure..

      Keep on modding and shooting and don't forget when you replace your compressor go one step up in cost to have allot better unit.

      Oh, and by the way that was a very very long post! I ate breakfast just before I started and by the time I was done I realized I had missed my lunch. ;^).
      There are a bunch of them out there. They are a viable method of providing air for our guns. Every one knows their limitations. My only concern is the potential for contamination of oil and moisture into the tank and or gun. It seems that many of you have a handle on that and have made these compressors work. Frankly I think unless you are going to go to the real high end stuff (Alkin) or comparable you are ahead using the YH over the middle of the road units which seem to fail about as often as the YH and are not especially user friendly with repairs. My opinion which is worth what you paid for it.