This is my third Piston and ring rebuild on my yong heng. I'd say I'm averaging about ten refills on 45 min scba tank refills from 3500 psi up to 4300 psi. I use 5 gal bucket with ice always and never run longer than 8 mins. Use regular hydraulic oil. Seeing how long your yong hengs last. Thanks
Three time Rebuild Yong Heng
- Thread starter RM.510bigbore
- Start date
My fist went a year , my second that I’m still on was new sept-19, my third is still in the crate from 2019? I have replaced 2 smile faces and 3 second stage pistons only, I’m guessing I average 1, 45 min tank fill per week, that’s 10-15 min fill from 3k to 4.2k, I shoot a lot, if I’m tuning guns double that, but I run a Miller cool mate through mine so I never break 50C. I run quinsyn compressor oil in it
Dump the Hydraulic oil!!!! Even the Home Depot synthetic showed signs of ignition. I switched to the SECO so far so good.
Smitty
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I think I passed the 2 year mark with mine. I used Royal Purple Synfilm for the 1st year & a couple months. Last oil change (March, '22) I used Husky. Next time I'm going to Seco lube. It's been FLAWLESS for me so far but have spare parts on hand just in case.
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I'm not sure there is anyway to make these compressor last, but I am having better luck doing the following.
Change oil every 10 hrs of run time - don't think it really matters just a good quality - Royal Purple or Seco.
Never run more than 15 - 18 min
Have been putting water pump in bucket with constant trickle of water from a hose and let the return just go on the ground - seems to keep a better constant temp this way - I think these machines are really temp sensitive with piston/ring clearances.
Change oil every 10 hrs of run time - don't think it really matters just a good quality - Royal Purple or Seco.
Never run more than 15 - 18 min
Have been putting water pump in bucket with constant trickle of water from a hose and let the return just go on the ground - seems to keep a better constant temp this way - I think these machines are really temp sensitive with piston/ring clearances.
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I don't understand why everyone seems to only run their units for 5-10 minutes. Once the unit has reached a stable temperature, and holding there, you'll add more wear from the Thermal Cycle than just keeping it at a constant temperature.
Smitty
Smitty
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Third year pretty much trouble free, but on second crank house, and that was my arrogant user error running it without an oil after an oil change (piston crank seized and crack the aluminum housing).
I am a high volume shooter and filling four 140c tanks average a month, about 15 minutes runtime 15 minutes cool down and repeat.
For me it is well worth the money, and now I keep a spare YH compressor in a crate if I would "ever" need spare parts.
I am a high volume shooter and filling four 140c tanks average a month, about 15 minutes runtime 15 minutes cool down and repeat.
For me it is well worth the money, and now I keep a spare YH compressor in a crate if I would "ever" need spare parts.
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I don't wanna jinx myself but... I am in the "good luck" category as well. I did make all the upgrades towards heat dissipation I could find on this forrum and I do keep good oil in it.
I have a bit over two years on mine and on a guess, I'd bet 25 to 30 hours of run time. I frequently use it to fill 45 minute scba bottles from 3500 to 4200psi.
One thing I have noticed is the line fittings are somewhat sensitive, probably due to the vibration that the thing makes. I find it neccessary to tighten them up every so often. And never, ever rotate any of the Foster fittings when under pressure, this is a quick way to destroy the o-rings within them. Vibration can be reduced by laying a 10lb bag of lead shot across the top of the unit. This also quiets the unit somewhat.
At first, I would never let the thing get beyond 120 degrees, but as time went by, the fact that I live in Vegas (stupid hot) I have been letting the unit run beyond thermal stabilization (just shy of 140 degrees) and then just stopping when I feel it's had enough....eventually the water will get too hot, but this would take a LONG time...I've never done it. As I mentioned above, I followed all the guidance I could garner here to help cool the thing. AKA fans-a-go-go. Also a higher volume water pump. I've never detected any of the fumes that others have, must be the oil.
And perhaps my dry environment makes a difference too. I dry both the air going in as well as the air coming out, but have never had to change out those dessicants. The air here in Vegas is quite dry most of the time, this year excluded. I frequenly purge moisture during a fill cycle and little more than a drop or two ever comes out.
If the unit failed, I'd fix it. If it went up in flames, I'd buy another.
My $.02 worth
Chris
I have a bit over two years on mine and on a guess, I'd bet 25 to 30 hours of run time. I frequently use it to fill 45 minute scba bottles from 3500 to 4200psi.
One thing I have noticed is the line fittings are somewhat sensitive, probably due to the vibration that the thing makes. I find it neccessary to tighten them up every so often. And never, ever rotate any of the Foster fittings when under pressure, this is a quick way to destroy the o-rings within them. Vibration can be reduced by laying a 10lb bag of lead shot across the top of the unit. This also quiets the unit somewhat.
At first, I would never let the thing get beyond 120 degrees, but as time went by, the fact that I live in Vegas (stupid hot) I have been letting the unit run beyond thermal stabilization (just shy of 140 degrees) and then just stopping when I feel it's had enough....eventually the water will get too hot, but this would take a LONG time...I've never done it. As I mentioned above, I followed all the guidance I could garner here to help cool the thing. AKA fans-a-go-go. Also a higher volume water pump. I've never detected any of the fumes that others have, must be the oil.
And perhaps my dry environment makes a difference too. I dry both the air going in as well as the air coming out, but have never had to change out those dessicants. The air here in Vegas is quite dry most of the time, this year excluded. I frequenly purge moisture during a fill cycle and little more than a drop or two ever comes out.
If the unit failed, I'd fix it. If it went up in flames, I'd buy another.
My $.02 worth
Chris
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I had a Nardi Atlantic 100 go out last year after several years of use. Purchased a Yong Heng and now have over a year of use filling guns. I have used Royal Purple so far with no issues. I don't notice any smell of oil nor does the oil turn black. Guess I'm satisfied with the oil and the compressor is still running strong.
The Nardi being a fresh air compressor uses a different oil specifically for breathing air compressors. Its cost is 2-3 times the oils cost of Royal Purple.
The Nardi being a fresh air compressor uses a different oil specifically for breathing air compressors. Its cost is 2-3 times the oils cost of Royal Purple.
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do You think, the ice cold (chilled) water would make the tolerances too tight for piston and piston rings? I don't recall which video, but some one had indicated to start with only cold water (not icy cold) until the compressor has stabilized pushing air into reservoir... give that a check..
And yeah, pls. switch to royale purple/seco compressor oil...
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14.0hrs of run time on my Yong Heng. Max 15 min run times but usually less topping of 6.8 liter tank (about 25bar to 30bar). I have replaced the high end piston and rings. The piston was the old style (weaker design) but replaced it with new version @ around 10-11hrs. Used Royal Purple first but switched to Husky full synthetic when I swapped pistons.
I run mine with ice water start to finish. I have over 60 fills with mine (and only about 3-4hrs on the top end rebuild.
***worth every penny***
I run mine with ice water start to finish. I have over 60 fills with mine (and only about 3-4hrs on the top end rebuild.
***worth every penny***
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Maybe you can direct me given your experience rebuilding these things. I’m trying to get mine to generate some pressure right now getting a little frustrated. It stopped building pressure a while back, only about 11 hours total run time. I replaced an o ring in the very top assembly with the little reed valve and that fixed it for a while, but it soon stopped building pressure again. I replaced the other o ring in the top assembly, that didn’t fix it. today I replaced the green “shim” (like a gasket basically) that sits under the assembly that covers the small inner piston. No improvement.
Low pressure air comes out of the nozzle pressure never builds up if the end is plugged or if it is attached to a gun.
I checked along the line between the compressor and the gun/tank and that all seems sound. Do you have another shim/gasket it would go between the black finned portion of the cylinder and the crank case but I doubt that is the problem.
Any suggestions for what to do next other than search forums and YouTube?
Low pressure air comes out of the nozzle pressure never builds up if the end is plugged or if it is attached to a gun.
I checked along the line between the compressor and the gun/tank and that all seems sound. Do you have another shim/gasket it would go between the black finned portion of the cylinder and the crank case but I doubt that is the problem.
Any suggestions for what to do next other than search forums and YouTube?
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Have you checked your pressure safety disc? It's the top brass plug that is in the manifold the high pressure head pumps into. On the right side of the compressor.
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Could be a number of causes. Check for leaks on all lines at fittings (and the burst disc as mentioned). Check the purge screws for leaks. If it is airtight from the outside then time to look inside. Sounds like you already looked at the high end reed valve. Check the high pressure piston head and rings. Sometimes the piston head on older units can crack. Mine broke apart at around 10-11 hours run time. Low pressure piston on older units have had instances of cracking where high pressure piston is attatched. The pistons on newer units have been beefed up. Older units can be retrofitted with the upgraded pistons.
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I think only the second stage piston is wore out but for $35 I just buy the rebuild kit. Thank you all for your similar experience with the Yong Heng. 
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Yesterday I past the 60 hrs with an original battery in the vibrationmeter.
Last year I finished my basement/rooms and wife kicked me out because of a RoyalP smell, now running the YH in my garage. Still a same oil.
To the people wanting to use ice and magic tricks with a water cooler........... cmon, just ran slow a cold tap water through a bucket and flush it consistently.
Last year I finished my basement/rooms and wife kicked me out because of a RoyalP smell, now running the YH in my garage. Still a same oil.
To the people wanting to use ice and magic tricks with a water cooler........... cmon, just ran slow a cold tap water through a bucket and flush it consistently.
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I use ultrachem Chemlube 751 and find the smell I used to get from normal low pressure compressor lubes is gone. This lube was actually designed for dive compressors unlike the other oils out there like husky and royal purple. I have no problem with anyone using those other oils btw..
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I find it amazing that people still are unwilling to use HP Compressor oils and think that regular compressor oils can be used without consequence.
There is no material difference between the YH and commercial SCBA compressors in the staging of compression to reach our needed pressures.
These pressures demand actual HP compressor oils, you are damaging your compressor by using anything but real, SCBA compressor oil.
Of course, the choice is yours but when you loose compression, blow the second stage, break the piston or fry rings, we really can't help you until you suck it up and use oils that are made for HP compressors.
2 years, 113 hours, top off two, 65sq ft tanks every week from 3k to 4k, still running strong.
There is no material difference between the YH and commercial SCBA compressors in the staging of compression to reach our needed pressures.
These pressures demand actual HP compressor oils, you are damaging your compressor by using anything but real, SCBA compressor oil.
Of course, the choice is yours but when you loose compression, blow the second stage, break the piston or fry rings, we really can't help you until you suck it up and use oils that are made for HP compressors.
2 years, 113 hours, top off two, 65sq ft tanks every week from 3k to 4k, still running strong.
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I can keep my upper. Cylinder cool with ice water, but the crank case and oil gets extremely hot. I run for 20 minutes and cool for another 10 minutes
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