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.

 

[SLICKNICK]

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.

This. The compressor should be on a 20A breaker. When it trips a 20A breaker now, and didn’t do it before, the problem is not in the breaker. The compressor is telling you it’s overloaded, and time to find out why. Common reason for tripping 20A is water getting into second stage (water doesn’t compress like air). And if detonation is occurring in second stage. Common cause of detonation is carbon buildup on second stage.

 

[Ratzy]

This. The compressor should be on a 20A breaker. When it trips a 20A breaker now, and didn’t do it before, the problem is not in the breaker. The compressor is telling you it’s overloaded, and time to find out why. Common reason for tripping 20A is water getting into second stage (water doesn’t compress like air). And if detonation is occurring in second stage. Common cause of detonation is carbon buildup on second stage.

It worked on the fridge 20a until the fridge kicked on. I didnt see it was ever on an isolated 20a.

 

[JimD]

Thanks for all the electrical engineering but I am an engineer. I understand electricity. But additional 20 amp outlets do not install themselves. I will probably put one in but not today. I think it is pulling more amps now because the piston rings are new and a little harder to move. The breakers do not pop on startup, they pop when I got up around 3500 psi. It has an oversize water pump and three fans pulling from the same power station so the full 15A was not available to the YH. The peripherals don't pull more than an amp or two, however.

I think I fixed my problem. I took the outlet area of the HP piston apart and thought maybe I had put on a wrong size O-ring for the air so I put in a thicker one from the ones I got with the compressor. This turned out to be a move in the wrong direction. But my reed valve was clearly loose, free to move, and I did not know which way was "right". I rewatched a youtube by Sam Cotton on the upper end and he only said "don't mess with it" but I saw the openings seemed to be pointed the same way as the water fitting on the bottom of the HP cylinder. So I put in a smaller O-ring (the thicker one was damaged from being squished) and oriented the reed valve that way and it seems to be working well. I had taken all the screws out that hold the case on to look under it for a leak and stupidly did not reinstall them before continuing with testing. I did an initial dead head and it went to 300 bar pretty quick when it was stopping at 4000 psi before. I got excited and hooked it to the bottle without thinking of the cover not being attached. The only really impact was it was even noisier than usual so I started reinstalling the screws and got a couple small burns on my arm from the HP air lines. I ran it for about 10 minutes and pumped the bottle up to 3900 psi - so 400 higher - but the water temperature got to almost 65 degrees C. I decided to shut it down, install the rest of the screws, and put some ice in the water for the next run. I'm not sure it will get to 300 bar in under half an hour like I wanted, that is still to be proven, but it doesn't stop at 3500 any more. After lunch I plan to do a run with ice and see if I cannot get the bottle to 300 bar. But even if it only gets close it is clearly usable at this point. A bit more of a pain to use with the increased electrical demand and the need for ice but usable. The electrical demand may also decrease when the piston rings wear in.

Thanks again for all the helpful suggestions (including the electrical ones).

 

[Ratzy]

After 45 years I'm still happily working as an Engineer. I much prefer my low voltage to household. I've always been able to find the hot wire .

But I always tell the kids it is all still Mr Ohm and Mr Watt and their laws.

 

[Scotty1]

Did you lube the pistons and cylinders with silicone when you reassembled?

 

[Ratzy]

Thanks for all the electrical engineering but I am an engineer. I understand electricity. But additional 20 amp outlets do not install themselves. I will probably put one in but not today. I think it is pulling more amps now because the piston rings are new and a little harder to move. The breakers do not pop on startup, they pop when I got up around 3500 psi. It has an oversize water pump and three fans pulling from the same power station so the full 15A was not available to the YH. The peripherals don't pull more than an amp or two, however.

I think I fixed my problem. I took the outlet area of the HP piston apart and thought maybe I had put on a wrong size O-ring for the air so I put in a thicker one from the ones I got with the compressor. This turned out to be a move in the wrong direction. But my reed valve was clearly loose, free to move, and I did not know which way was "right". I rewatched a youtube by Sam Cotton on the upper end and he only said "don't mess with it" but I saw the openings seemed to be pointed the same way as the water fitting on the bottom of the HP cylinder. So I put in a smaller O-ring (the thicker one was damaged from being squished) and oriented the reed valve that way and it seems to be working well. I had taken all the screws out that hold the case on to look under it for a leak and stupidly did not reinstall them before continuing with testing. I did an initial dead head and it went to 300 bar pretty quick when it was stopping at 4000 psi before. I got excited and hooked it to the bottle without thinking of the cover not being attached. The only really impact was it was even noisier than usual so I started reinstalling the screws and got a couple small burns on my arm from the HP air lines. I ran it for about 10 minutes and pumped the bottle up to 3900 psi - so 400 higher - but the water temperature got to almost 65 degrees C. I decided to shut it down, install the rest of the screws, and put some ice in the water for the next run. I'm not sure it will get to 300 bar in under half an hour like I wanted, that is still to be proven, but it doesn't stop at 3500 any more. After lunch I plan to do a run with ice and see if I cannot get the bottle to 300 bar. But even if it only gets close it is clearly usable at this point. A bit more of a pain to use with the increased electrical demand and the need for ice but usable. The electrical demand may also decrease when the piston rings wear in.

Thanks again for all the helpful suggestions (including the electrical ones).

Glad you found most if not all.
I have a Tuxing dual cylinder awaiting the rebuild kit.

 

[JimD]

Well the after lunch test was a success so I am considering it fixed. I'll have to do some shooting and get the bottle down to the low 3000s like I normally do before refilling but I pumped the bottle from 3800 to 4400 psi with temperatures never over about 63 C but I had to put in four frozen soda bottles to keep the temperature down. Took 15 minutes. If I start at something like 3200 will it get done in half an hour? Should be close. The pressure fell from 3900 when I last turned the YH off to 3800 when I opened the bottle's valve. A little of that was filling the line to the second filter (where there is a one way valve) but I think a lot of it was the air cooled. So I went slightly over 300 bar. It's nice to get my "bottle filler" back. I think it is working pretty well for a 4 year old $300 compressor. Worth the $20 rebuild kit. I'm still hoping the compressor temperature may fall a little once the new parts are broken in.

For those focused on the electrical side of things I have not had any breaker flips since I plugged the YH into what I believe is a 20 amp circuit in the garage next door to the storage room the YH is in using a short extension cord that I think is probably 16 gauge. I don't think this is an ideal or permanent way to hook it up but for now it works. I will probably add an outlet in the room the YH is in that is on a 20 amp line with no other loads while the YH is working. But that means tearing into the walls so it will be a bit before it happens.

My degree, a lot of years ago, was Mechanical Engineering. I did the electrical final for a major expansion of my home much more recently which included hooking up a second heat pump. I wired my shop. I am pretty comfortable doing electrical work but I do it when I have plenty of time. I even have hooked up a few new emergency exit lights volunteering at my church. That circuit is 277V and cannot be turned off due to the battery backups. Working with 277 on the top of a 12 foot ladder isn't exactly fun but it can be done. Adding one 120V outlet to a line that I can turn off is not a real big deal. Just need the time. I have an outlet in my GR that isn't working and a 3 way switch acting up too. The YH will have to wait at least a few days or I'll use the extension cord. I feel a lot better now that I know it is working OK.

 

[Air King]

I've a Vevor rectangle box type with auto shutoff, I feed it silicone oil and silicone gel in the two ports where the crossover tube is connected on the piston housing, then run with drain hoses connected to the outlet and bleeder to flush it out. I also use a syringe with a long bent needle and feed a bit of silicone oil into the air inlet on the face of the piston. I do this about every hour of pump use, it flushes it out and keeps it moving. I also put silicone gel on the piston stem between the piston housing and the motor, use a syringe with a large bore needle.

You must use silicone oil of course and no aerosol, petro oil and aerosol gas could explode in the piston.

As for your issues, OP, I'd brush soapy water on all fittings to see what's leaking, to include the oil water filter hoses and airgun fill port hose. My compressor was leaking at the oil water filter fitting and was fixed with an o-ring.