Alright back to rebuilding Yong Isn't again. Oil has been getting dirty faster than normal. Put 2nd new compete upper lower piston and upper piston in new gaskets ect. Sounds good put not building pressure. Checked for air leaks all good. Could I have wore out the upper cylinder that is aluminum ? Any experience appreciated!!
Yong Heng 4 th new piston.not building pressure!!
- Thread starter RM.510bigbore
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I've ZERO experience YET with rebuilding a YH. It'll come sooner or later I know. In my 3rd year with mine. Upper cylinder isn't too expensive. I'd replace it just to be sure. WHY 4 rebuilds? I'm curious.
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Check valves? I’d imagine it’s all clean and check valves are clear? Did you check the reed valves?
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I changed the valve in the upper cylinder with head gaskets supplied with the rebuild kit. I'm going to check it some more . Maybe in a lil while order new cylinder heads. This is also my third year with the yong heng . I shoot alot with my Texan 50 it eats air. I'm only getting about 7-10 fills on 45 min scba tanks 3600 to full 4200 psi fill. 8 minutes run intervals. Ice in water 5 gal bucket. Before needing upper cylinder piston. Yong Hong $230.00 real compressor or booster pump$3500.00.and up. If I ever have money to buy something good it will fill to 5500psi to fill my Scott 5.5 bottle. Then I'll 5500 psi and regulate down to 4500 psi or 3625psi. One can dream
Until then I'm going to be real handy with yong hengs
Until then I'm going to be real handy with yong hengsUpvote 0
Nothing wrong buying a $250 YH every second or + year, I have one complete spare still in the box, where I can salvage parts in case of emergency until aliexpress arrives. I had a crankshaft seized last winter I also replaced the entire lower + higher pressure parts that I bought (on time) as a kit from ali.
Answer to your first post, no cylinders not wear so fast as the piston rings.
Answer to your first post, no cylinders not wear so fast as the piston rings.
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I'm not quite understanding this sentence. "Put 2nd new compete upper lower piston and upper piston in new gaskets ect", maybe just because I'm not familiar with the Yong Heng terminology. I know on my AV 4500 that 90% of the time when it's slow building pressure and oil getting dark too early it's the three high-pressure seals on the small diameter brass piston. Sometimes it's apparent they are bad but sometimes they look ok but when I go ahead and change them, I'm normally back in business. I also clean and polish all the reed valves and seats while I'm at it. I haven't pulled the check valves in a while but probably need to. Good luck on getting it compressing again.
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Your top end is worn. Getting a new piston and head assembly is probably the cheapest and easiest route. I rebuilt my two "spares" last week with new piston assembly units. Next time I'll need a jug and head assembly. BTW, I change my oil a lot and it helps with longevity, especially with a machine that is used a lot like your's.
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On the crank end of the connecting rod, I drill the beginning of the oil passage hole bigger and oblong (like a funnel) so the oil feeds into that journal easier.
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Naha true boosters will run you something like 4500psi output way easy.I changed the valve in the upper cylinder with head gaskets supplied with the rebuild kit. I'm going to check it some more . Maybe in a lil while order new cylinder heads. This is also my third year with the yong heng . I shoot alot with my Texan 50 it eats air. I'm only getting about 7-10 fills on 45 min scba tanks 3600 to full 4200 psi fill. 8 minutes run intervals. Ice in water 5 gal bucket. Before needing upper cylinder piston. Yong Hong $230.00 real compressor or booster pump$3500.00.and up. If I ever have money to buy something good it will fill to 5500psi to fill my Scott 5.5 bottle. Then I'll 5500 psi and regulate down to 4500 psi or 3625psi. One can dream
From room preaaue to 4500psi (they work past 5000psi no roblem!): https://www.altaros.cz/compressors/169-altaros-hybrid-compressor-booster-unit.html
That thing will take any feed pressure from room/14.5pai to 4500+psi.
It will work of a shop compressor or off the supplied pressure regualtor, that is supplied from the same HP feed bottle.
This one is a true booster: https://www.altaros.cz/compressors/160-altaros-double-booster-b2b-edition-bottle-bottle.html
It wont work much below 500psi feed pressure, and is meant to boost from a bottle to a gun in the field.
It will also work at home if you have ample supply of above 500+psi and a shop compressor to supply the work.
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Altaros boosters are cheaper than "real scuba boosters" and work great. The only finicky thing is don't overtighten the check valves, hand tight only. Otherwise the solenoid valve they use to shift work air side to side is brilliant.
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Thank you all for your input. I'm going to order both cylinder heads and prob another spare yong heng. Chicken thief you are right the altros booster is probably the only reliable way to produce high pressure air at home reliable under $1000.00. I'm saving up hope to one day have a booster pump
. Until then ill keep shooting and playing with the yong heng. Thank goodness for the support here
. Until then ill keep shooting and playing with the yong heng. Thank goodness for the support hereUpvote 0