Yong Heng oil changes

That looks like a piece of gasket, might of fallen in to the cylinder when you took it apart.....how thick is it?....can't tell from your picture. It is not part of your piston assembly. Also it may be a part of the valve seal in the head.

Hydraulic fluid is flammable. Could it start dieseling when it gets past the first stage?

My first filter which is just cotton catches the oil before it gets to the Tuxing and it's brown. So it does get by and get hot too. 

That looks like the top land of the piston, but the picture he posted showed no damage on his. If he posted a pic of a good piston, different than the one from his compressor, how does he expect anyone to diagnose his problem? Looks to me that we have a troll here. If so, he can figure out his own problems from now on.

Looks like it could be this issue.

This image is from a recent post on facebook PCP Compressors & Tanks, "The Good, Bad and Ugly".

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Yep this is EXACTLY what I found.

Many thanks Rodeo for finding this picture/link!

Exactly what caused this? Is it a common problem?

Ok Steve. Why don't you pm me your email or cell number and I can email or text you copies of the pages.

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Me too.......PLEASE!?

I don't know where you found it but man will that ever help when I need to do some repair again. Not soon though

Don't have a link but Aliexpress has the parts, type in "yong heng parts" in the search engine. You can buy the 1st/2nd piston assembly for like 12-14 dollars. I get 2 -3 at a time for spares. It broke from oil detonation eroding the top of the piston away. Using a Compressor oil can help reduce this problem.

Queequeg, I don't know the properties of hydraulic oil, but that is what the Yong Heng factory specified for use in their compressors; (AW #46 Hydraulic oil). I don't use it anymore, but I did in my first Yong Heng and for awhile in my second one. It is all speculation about what is best to use, but I suspect that just about any oil will work. the oil does not get hot in the crankcase and very little gets past the rings into the compressed air supply.

Looking at the piece that I have it looks to be made of some kind of sintered metal which is pretty brittle. It might be made that way as a break-away to avoid further damage of the high compression side. Just guessing.

I bought my yong heng as a backup for my omega air charger and have been using the AW #46 in it ever since with no problems knock on wood, I've had mine 2 years now and only change the oil when it starts to turn brown, I changed it last week after filling my scba bottles several time usually from 3000 to 4500psi and the oil was still as clear and clean as when i'd changed it a couple of months ago.

I bought my yong heng as a backup for my omega air charger and have been using the AW #46 in it ever since with no problems knock on wood, I've had mine 2 years now and only change the oil when it starts to turn brown, I changed it last week after filling my scba bottles several time usually from 3000 to 4500psi and the oil was still as clear and clean as when i'd changed it a couple of months ago.

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Given mine only lasted a year with only 11 hours I guess it's time to reevaluate the oil I'm using which is Royal Purple.

As far as I am aware it isn't being run hard and put away wet. Start up and shut down precautions are being done properly.

No overheating issues.

Time to try the AW#46. Which brand are you using and is it common enough to buy locally?

Thanks!

Hardback.

I think I got my AW 46 from Oriley auto parts. it is not hard to find. I am going to switch from the purple stuff to the Husky synthetic compressor oil from Home depot though, since it is clear and easier to tell when it's dirty.

Thanks for the update with switching to Husky oil.

This is what I originally stared out with.

Just to let you know Amsoil full synthetic ISO 100 30/40 is also water clear. Just opened a quart I have on standby to see.

I'm wonder if my YH is good enough to deserve Amsoil

One more fail and it's going to get parted out

I'll then get a Shoebox f10.