Yong Heng after piston replacement

[JimD]

My Yong Heng started taking 45 minutes to refill my 45 minute Scott air pack from 3000 psi to around 300 bar. It really struggled as it got up around 4000 so I did not always take it to 300 bar. It used to do this in 20 minutes. So I ordered a piston/rod assembly from Amazon and installed it this morning.

I would not call the installation very easy but it was not terrible either. But with the new piston installed I cannot get my bottle to go over 3500 psi (where it started). It also trips breakers much more than it every has but I got it to run for 15 minutes but it stayed at a pretty constant 3500 (using the gauge on my fill set, not the crummy YH gauge). The temperature is up a little, 10 degrees or less, but it's hotter here now so that is probably at least part of it. The big issue is it won't even do as well as the old piston did in terms of filling my bottle. It will go to 4000 psi on a dead head test but slows down a lot over 3500 psi.

It might be leaking a bit somewhere around the gauge. I don't think it's the gauge itself but might be. The gauge is new (but that doesn't prove anything). I will check more for leaks, probably tomorrow (tired of messing with it right now).

Other things I should check?

 

[Bladesx]

It might take a bit for the piston and Rings? to seat. Likley you did not check the cylinder bore for a taper from wear which will not allow you to get full output do to blow by. ramdom thoughts.

 

[WorriedMan]

Slowing fills for any compressor means time for dead head pressure test with soapy water spray on all parts of the system. First slow fill encounter for me brought needless removal of high-pressure head, bad quick-disconnect "O" ring was real culprit. Lesson learned, next time found YH gauge leaking and worn Delrin washer under pressure-release screw. Unsure of reason why replacement parts are underperforming, I've only heard of similar when an owner tried to install authentic Yong Heng replacement parts in an, unknown to him, non-authentic Yong Heng compressor. WM

 

[Ratzy]

When I have enough blow by in the high pressure side to slow things down around 3500-4000 psi I get air and maybe oil out the breather plug.

If you are not getting at least some air pressure out the breather plug you may have a leak elsewhere in the system.

 

[SLICKNICK]

take hi pressure head off and check seals, and also check the round check valve on hi pressure cylinder head. Too much carbon buildup cause detonation, and can trip breaker. Clean or replace. Kits on Amazon are inexpensive

 

[JimD]

I will definitely check the breather plug and also the other things mentioned particularly leak check. I had the check valves out and they look fine and the reed valve is clean. I put new O-rings in the top end. I was surprised that it repeatedly tripped breakers but it may be more surprising that it didn't before. I had the YH and all it's peripherals plugged into the same power strip rated for 15A. So the first couple trips were of the power strip breaker (15A). Next I plugged it into a Milwaukee power supply that has powered it before but is only rated at 1800 watts if I remember right, may be less, and wasn't fully charged. It worked for a minute or two but then complained, possibly just because it was not charged fully (or even close). Next I plugged it into a 20A circuit that also has my refrigerator on it. I think it worked until the frig started up then the breaker tripped. Finally I plugged it into a circuit in the garage that I don't think had anything on it. Might not even be 20A and I had to use a short extension cord. It ran fine on that circuit for 15 minutes but it wasn't getting anywhere so I turned it off. So the breaker tripping may be more normal for YHs. If I can get it working satisfactory except for breaker trips there are 2 20 amp circuits going to my shop I can put an outlet on and it should resolve the breaker issue. If I am running the YH I won't be in my shop using the table saw or dust collector.

 

[SLICKNICK]

PCP Air Compressor Replacement Parts Kit, 2 Hole 4 Hole Paper Gasket Sealing Ring Filter Nozzle, Made of Metal, PVC, Applicable for 30mpa Air Pump Pressure - Amazon.com

PCP Air Compressor Replacement Parts Kit, 2 Hole 4 Hole Paper Gasket Sealing Ring Filter Nozzle, Made of Metal, PVC, Applicable for 30mpa Air Pump Pressure - Amazon.com

a.co

That small round disk, gets carbon build up after a while. If too much builds up it, will diesel (Detonate) . When that occurs, the temperature goes up faster that usual, and hotter than usual. It will also destroy the hi pressure rings on hi pressure piston.

 

[Ratzy]

I will definitely check the breather plug and also the other things mentioned particularly leak check. I had the check valves out and they look fine and the reed valve is clean. I put new O-rings in the top end. I was surprised that it repeatedly tripped breakers but it may be more surprising that it didn't before. I had the YH and all it's peripherals plugged into the same power strip rated for 15A. So the first couple trips were of the power strip breaker (15A). Next I plugged it into a Milwaukee power supply that has powered it before but is only rated at 1800 watts if I remember right, may be less, and wasn't fully charged. It worked for a minute or two but then complained, possibly just because it was not charged fully (or even close). Next I plugged it into a 20A circuit that also has my refrigerator on it. I think it worked until the frig started up then the breaker tripped. Finally I plugged it into a circuit in the garage that I don't think had anything on it. Might not even be 20A and I had to use a short extension cord. It ran fine on that circuit for 15 minutes but it wasn't getting anywhere so I turned it off. So the breaker tripping may be more normal for YHs. If I can get it working satisfactory except for breaker trips there are 2 20 amp circuits going to my shop I can put an outlet on and it should resolve the breaker issue. If I am running the YH I won't be in my shop using the table saw or dust collector.

Most of these compressors are 1800 watts.

I=P/E
1800/120 = 15 amps
If your voltage drops below 120 the current goes up. Weather has been hot. Everyone running their A/C. Local service voltage drops due to load.
1800/115 = 15.65 amps
Pop goes the 15 amp breaker

Though the 1800 watts is worst case scenario like starting the compressor under load. Once it is running it should not use anything like 1800 watts until it gets to high pressure.

 

[Scotty1]

I will definitely check the breather plug and also the other things mentioned particularly leak check. I had the check valves out and they look fine and the reed valve is clean. I put new O-rings in the top end. I was surprised that it repeatedly tripped breakers but it may be more surprising that it didn't before. I had the YH and all it's peripherals plugged into the same power strip rated for 15A. So the first couple trips were of the power strip breaker (15A). Next I plugged it into a Milwaukee power supply that has powered it before but is only rated at 1800 watts if I remember right, may be less, and wasn't fully charged. It worked for a minute or two but then complained, possibly just because it was not charged fully (or even close). Next I plugged it into a 20A circuit that also has my refrigerator on it. I think it worked until the frig started up then the breaker tripped. Finally I plugged it into a circuit in the garage that I don't think had anything on it. Might not even be 20A and I had to use a short extension cord. It ran fine on that circuit for 15 minutes but it wasn't getting anywhere so I turned it off. So the breaker tripping may be more normal for YHs. If I can get it working satisfactory except for breaker trips there are 2 20 amp circuits going to my shop I can put an outlet on and it should resolve the breaker issue. If I am running the YH I won't be in my shop using the table saw or dust collector.

The YH definitely needs a 20 amp circuit to start and run correctly. Repeatedly tripping a 15 amp breaker on startup is hard on the already overtaxed motor and start windings. These things run at the very edge of their build design and quality.