Yong Heng Arrived-First Impressions

The battery is LR44 battery, pretty much everywhere. The probe goes in to a small hole on the back of piston cylinder, you just press it in.

Double post it did not post and gave an error so I did it again.

I used the 357 batteries in mine. There are other Chinese knock offs with different numbers that won't last as long around though. Yes, it snaps into the hole in the cover and yes, the sensor goes into the hole in the head.

Doesn't matter what you seal the drain plug with so long as it can handle being exposed to oil.

Lots of You tube vids out there on set up and running the Yong Heng. Some are decent while others will mislead you and still others the people don't know what they are talking about and even break their compressors while trying to fix them. So use some judgement as to who you want to believe.

Just remember these main points and you should be fine.

Edited and Current 6/12/21

Here is my standard post to all things Yong Heng hope it is helpful.

The Yong Heng "Simple" version least expensive does not have a water separator you need one.

If you messed up and got the “Simple” version you can get parts on Aliexpress to fix it for <$40

The "Auto Stop" version shuts off near 3000psi probly not a good thing for most people.

So you likely want the "Hardcover" or "Set Pressure" versions your choice on the 110V or 220V.

Shipping has gone up so this may not be the least expensive place to buy anymore but it does show the difference in models which is important.

https://www.aliexpress.com/item/32824234795.html?spm=a2g0o.store_home.productList_13760454.subject_2

Never start them under pressure. I should have put this in here sooner.

Give them a dedicated 15amp outlet 20 would be better. They draw a bit of juice on start up especially the brand new ones. Don’t Use an extension cord unless it is short and has an honest 15+ amp rating. Preferably 12ga wire so you will not have problems.

ISO 46 may no longer be recommended although I used it for a year without failure. I am currently using the Husky Brand Synthetic or synthetic blend oil, found at Home Depot, for two years now without a problem. Top it off to the red circle in the sight glass. This oil is clear so you can see when it gets contaminated.

Don't push your air fill past the compressor’s spec which is 4350psi. A little less is usually better than the max, and the Yong Heng should last for years unless you get a bad one.

I did my first oil change at about an hour, it was extremely dark colored. I went far longer, between changes, after that.

I have two YH compressors bought the second as a backup for the first as I, fergot to turn on the coolant pump several times and, overheated it until it smoked. It did not like it but it continued to run just fine. Still I did not trust it after that. I added a switched outlet, to the system, so it turns the pump on before the compressor will power up to keep me from doing that from now on.

The second one, my back up unit, died in about two months bad QC from the factory. Cost me $12 for a new second stage piston and an hours’ time to replace it. Then to add insult to injury I fergot to put oil in, the latest unit after I put it back together, and ran it for several minutes without any. So I filled it with oil and it fired up and somehow still werqs fine. The #1 unit that I was worried about, cuz I overheated it so many times, just kept on filling my guns and tanks till I got #2 repaired and retired it.

I do not fill past 4200psi as when I do, all too often, I blow a burst disc. This may not happen on the first or second fill but soon thereafter it will.

The temperature sensor only measures head temperature so running it much over 20-30 minutes can overheat the motor and other parts even if ice is used in the coolant. Ice or a container of it, in the coolant, is a good idea especially if you are like me and do not use the full five gallons of water as suggested in the manual.

Keep your water supply level with the compressor to be kind to the pump and assure a good supply of coolant goes through the compressor.

I recently started using this Red Line water treatment after I noticed algae growth in my 2.5 gallon water bucket every few months. It seems to have stopped or significantly slowed the algae growth. I will know more in a few months.

https://www.autozone.com/antifreeze-radiator-additives-and-windshield-wash-fluid/coolant-water-wetter-additive/red-line-water-wetter-super-coolant-12oz/486218_0_0

Keep your moisture filters, guns and tanks being filled above the compressor to help keep the moisture out.

Purge the system of moisture, using the screw valves on both sides of the compressor, for a couple of seconds every five minutes while in use.

Change out your small YH filter every twenty minutes and set the old one out to dry and reuse later.

Add a better filter if needed to be sure more moisture and any oil smell is removed from the system. Many of us use this Tuxing three media filter although, if you feel the need, you can change media types at any time.

https://www.aliexpress.com/item/32891898253.html

A smaller one will probly do for some.

https://www.aliexpress.com/item/4000960926898.html?spm=a2g0s.9042311.0.0.2a034c4dL0nrJU

Possibly a filter similar one of these if humidity is high in your area and your desiccant filters have to be replaced often.

https://www.ebay.com/itm/30MPa-High-Pressure-Air-Filter-Oil-Water-Separator-For-Air-Pump-Air-Tank/402600939671?hash=item5dbce2d097:gRoAAOSwy41f00pY

https://www.aliexpress.com/item/33032569946.html?spm=a2g0o.productlist.0.0.56fc60ccm8gTGq&ad_pvid=20210607072408105818162084010006558357_1&s=p

Bleed the pressure before you turn the unit off and let it run a few seconds to get the better part of the moisture out of the system. I have found that I blow less burst discs if I bleed before shutting down so I do this religiously.

Let the coolant pump run for a few minutes after shutdown to cool things off.



Info on the radiator install.

https://www.airgunnation.com/topic/yet-another-yong-heng-mod/?referrer=1

Here is a video on how to fill a SCBA tank.

https://www.youtube.com/watch?time_continue=157&v=_grx5p_R8D4&feature=emb_title

Another tidbit of info since you don't have the manual.

The output of your water pump goes to the bottom fitting on the second stage head on the compressor. The top fitting is your return line.

Enjoy.

I just installed a hotloop thermometer on mine. It uses one double A battery and you can turn it on and off. I got it on ebay for $15 shipped.

There's two common problems with cooling these that I've noticed out of the box. First check your upper cooling elbow on the head. The elbow threads are sometimes to long and if they are screwed in to far they will plug the circulation hole in the head. Second check your water pump to make sure the flow door on the back is fully opened to allow as much flow as possible. 

Also if you take out the brass plugs your pressure release handles screw into I'll almost guarantee you they'll be packed full of aluminum shavings.

Another thing is don't over fill your oil. Sit the compressor level and fill the oil to half way up on the glass.

OK, found two LR44 batteries, installed, fed wire under top cover, inserted probe in head and snapped in temp gauge. Guess Celsius display, is only option. I suspect two black plastic knobs with threaded rods fit into brass air vents on either side of pump. Both thread in but stop with about 1/2 inch of thread still showing. I noticed threaded rods have machined rounded point so they must seat against something.

WM

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That is the pressure release valves. You can watch some YouTube videos on operating and it'll save you some blown pressure disc.

A LOT of great info there but I would recommend doing something different for the coolant. Go with a 'sealed' system like in the picture, I use a 5 gallon bucket with well fitting holes, but the storage tote idea gives more coolant volume. 

I've seen pictures of what regular water, with all of its dissolved contaminants, can do to the internals of the water jacket so I use distilled water with mine and use a surface tension reducer like Water Wetter top increase the waters ability to soak away heat. 

My rifle takes less than 2 mins to top off when it falls off the reg so heat has never been an issue. 

The original pump on mine failed in a few months after recieving it but I got a much better, higher flow rate one, fairly cheap on Ebay.

Hi Worried Man, I just used my Yong Heng I received about a week ago, Without reading through this whole thread, I used two 357 batteries for the temp gauge, worked just fine In stead of snapping that temp gauge in place I just layed it in the opening and it seemed to be just fine while the pump was doing its thing. I just filled a 90ci bottle from zero to about 4200 psi, its now cold to about 4000 psi. It took about 10 mins. but I stopped and stated it about three times when it reached about 61C to let things cool off and left the water circulating to help cool it. Like everyone recommends I did the drain valve each time and also dropped the pressure to avoid a hard start. One thing I did notice is that that high pressure pipe heats up surprisingly fast! I think Im going to enjoy that pump! Im not missing the hand pump at all!

I believe the white plastic donuts go in the bleed fittings later when you need them. The pressure relief/bleed knobs screw down on them and then the unit holds pressure. Don't over tighten or they will not werq anymore. They are what you want to turn out and release pressure and moisture with, for a couple seconds, every five minutes while the unit is running. 

I think one goes in the gauge hole to seal the gauge as well.

There is nothing wrong with the stock temp gauges they werq fine. The 357 batteries last much longer, like a year or two, than the cheap junk LR44s do. Know your batteries;

https://www.reference.com/world-view/difference-between-357-battery-lr44-f4873b8f11d5bdf7

A little ice in your reservoir will help keep things much cooler and cooler is better. You really don't need the fancy close looped system but if you are bored and have sixty to a hundred bucks that you don't need, depending on your radiator and fan choices, then it will give you something to do for a bit.

I used a thin coating of thermal paste on the temperature probe before inserting it into the hole in the high pressure head. Helps hold it in place and provides better thermal contact.

I used a thin coating of thermal paste on the temperature probe before inserting it into the hole in the high pressure head. Helps hold it in place and provides better thermal contact.

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Never thought about that! Given that I use thermal "grease" when working on computers all the time, one would think I would have thought about that. Go figure... old age? LOL!

Thanks for the tip! Although I don't own a YH and only have hand pumps, I'll have to try and commit this one to long term memory for future use! (smile)

I used a thin coating of thermal paste on the temperature probe before inserting it into the hole in the high pressure head. Helps hold it in place and provides better thermal contact.

Click to expand...

Good idea that is. But mine is difficult to get out as it is tight.