Shade tree repair of Yong Heng Compressor

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far_shot

far_shot

Member
Jan 21, 2018
359
17
Ia, United States
I started getting a lot of oil (more than usual) out of the purge valve and decided to investigate when it showed up in the first of three cotton filters.Of course, the cylinder gasket and head gasket broke when taking it apart and I had to make new ones as they are not included in the parts kit that came with it. Nor are the piston and high pressure rings :( I found the top two ring on the low pressure piston end gaps were aligned instead of 120 degrees apart and was probably some of the oil cause. High pressure piston and flat valves were really grimy. Cylinder was glazed so I put in new cross-hatch with a roll of 400 grit on a drill mandrel. Got rid of the glaze, but not the ventricle scratches. Seemed to have a lot of wear considering it has never ran more than a few minutes at a time and has had one oil change. Probably not even 5 hours of total run time. Most all of the parts can be found on Ali Express... if you look far enuf, but I'm just going to assemble it and see what it does. I should report back tonight or tomorrow. 

1547927463_6829591985c437fa75d4667.95869631_fffffxxx.jpg
1547927645_6663438685c43805d8c87c2.61972608_crank.jpg

 
Ahh.. Bummer to hear about your excessive oil issues..
It's cool to see that you've torn into it, and are checking it for potential causes..

I always guessed that the rings could be an issue - causing slight blow-by..

Being that the crank to con-rod has no bearing and is steel to aluminum, 
I figure there would be eventual wear there too - possibly causing a bit more vibration 
then causing piston/ring to cylinder wall wear - you noticed glazing though..

Good idea to give it a cross hatch..
I used to have an el cheapo cyl hone that I figured would work - if need be..
Glad your method worked.

It'll be nice to see your results, and Hopefully, they'll be much better this time around.

Good luck, and thank you for sharing this!


Sam -
 
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I repeatedly catch fire from people for saying this, but these YH compressors just flat out were not built to last. I keep hearing "well it is cheap enough that I don't care if it breaks, I'll buy another." Alright, that is a reasonable perspective if you're willing to play that game. At some point though, for me, this is a hobby and I want my toys to work. Playing the "my compressor crapped out on me and now I need to fix it before I can go play" game a bunch of times in the first 6 months of ownership just ended up not being my style. Given that the AV Nomad II is twice the price for what is at bare minimum a unit warrantied for a year and much nicer in function (quiet enough you don't need hearing protection, doesn't walk around when running, doesn't require messy coolant, etc) even if it runs reliably for a year and craps out I broke even financially as compared to my YH and didn't have to deal with the stress of constant breakdowns/repairs. *shrug* 



I think part of the issue with compressors and reviews of them is the number people own. You don't usually get excited about compressors, so you find one that works for you and you stick with it. This is as opposed to rifles where you buy more than you technically need just because you like them. This means the power of comparative reviews is dramatically reduced, because there is a lot less experience base. Some guys on here own dozens of guns, but I'm guessing one maybe two compressors. Really reduces the amount of experience comparing advantages/disadvantages of different systems. So we all come to the table with experience on the one, maybe two, systems we've passed through our hands. Makes it hard to come to an informed consensus on what is good and what is bad compressor-wise. *shrug* 
 
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I hear you STO. Quality of materials is probably the down fall of the Yong Heng.You can get a complete top end for less than $100.00 and pretty simple to replace. I did succeed with this one. Ran it several times with no load and then capped it off...went right up to 300 bar with just a smudge of oil. Kinda tricky to deal with the top end as the disc valves and brass seat have to be orientated correctly and there is nothing to hold them in place when the head is bolted down. I greased them a bit and got it right the first time. (My 20 years of working with industrial pneumatics helps) The con rod and lower piston looked great....but it has not been abused with long runs....I only fill the guns and not a big tank.....so it has had a pretty easy life.

1547949015_11601905405c43d3d797e1d9.54802840_IMAG1056.jpg

 
Upvote 0
I repeatedly catch fire from people for saying this, but these YH compressors just flat out were not built to last. I keep hearing "well it is cheap enough that I don't care if it breaks, I'll buy another." Alright, that is a reasonable perspective if you're willing to play that game. At some point though, for me, this is a hobby and I want my toys to work. Playing the "my compressor crapped out on me and now I need to fix it before I can go play" game a bunch of times in the first 6 months of ownership just ended up not being my style. Given that the AV Nomad II is twice the price for what is at bare minimum a unit warrantied for a year and much nicer in function (quiet enough you don't need hearing protection, doesn't walk around when running, doesn't require messy coolant, etc) even if it runs reliably for a year and craps out I broke even financially as compared to my YH and didn't have to deal with the stress of constant breakdowns/repairs. *shrug* 



I think part of the issue with compressors and reviews of them is the number people own. You don't usually get excited about compressors, so you find one that works for you and you stick with it. This is as opposed to rifles where you buy more than you technically need just because you like them. This means the power of comparative reviews is dramatically reduced, because there is a lot less experience base. Some guys on here own dozens of guns, but I'm guessing one maybe two compressors. Really reduces the amount of experience comparing advantages/disadvantages of different systems. So we all come to the table with experience on the one, maybe two, systems we've passed through our hands. Makes it hard to come to an informed consensus on what is good and what is bad compressor-wise. *shrug*
Click to expand...

Doesnt the nomad only fill direct to guns? You're comparing a compressor that costs 2x the price and half as useful. I use my compressor to fill a 60min scba if it cant do that i wouldn't buy it. But sure some people thats fine for them.

I dont think anyone will argue with you that yh arent built to last. But parts are cheap and available.
 
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