Hong heng pressure is

[cajun1.]

it will not pressurize over 2500 psi . It keeps trying but leaks out the crank case. 

Anybody have a similar problem or familiar with the workings and know what to change?

 

[airgunfans]

The crank case is not air tight as air can leak through the breather tube by design. There must be some other places leaking. In my case, it's the external fittings but there has been reports on leakage at internal check valves, piston rings and etc. 

 

[advocate2]

My Yong Heng arrived last week. It works fine up to 3000 psi. After that the pressure meter on the Yong Heng rapidly rises into the red. I watch the temperature and always stop when the temp hits 55C, which happens is less than 5 minutes of run time.



Since I bought it from Walmart and paid the sales tax, should I just return it and get another?

 

[willy]

To the first question,its called blow by.need to replace the 4 top rings.Just a little silicone grease on the rings when assailable

.

 

[cajun1.]

I know the crank case isn’t air tight, I was just explaining that it wasn’t an external issue and if anybody knew what O-ring or whatever would cause that, before I tear it down. I know some one has tore it down before and could give me a tip of what to do or not to no and maybe. Or how it set up in there.

 

[advocate2]

I just checked Walmart to see what they had for another Yong Heng. There is only one listing. When I ordered two weeks ago there were 10. I wonder if they had too many returns and decided to stop selling the compressor.

 

[cajun1.]

 I appreciate the response. I was asking so if their was something I needed to know or be careful about from someone that did it before me. 

I made and installed a head gasket in my other one and it strains and stops and buzzes like the motor is weak. It was filling my gun bulldog 480 extended reservoir to 4500 but it can’t anymore so I have to work on it also.

 

[Fly]

I would fill a spray bottle soapy water turn on your compressor & spray the soapy water on all fittings ect. You will see bubbles if there

is a leak. Mine was were the pressure gage screws in. I pulled it & put another Teflon washer on top of the one already there & 

screwed the gage back in. It still had a small leak. I pulled the gage & wrapped the gage threads with a wrap of Teflon tape. Fixed & never

had another problem. These machines with that much pressure just must be checked from time to time this way. Your compressor came

with spare washers & seals. Hope this helped! 

Fly

 

[cajun1.]

55 isn’t really hot. I don’t remember what I run mine at but I think 70. Use two five gallon buckets when the water Warms up change buckets. 

 

[airgunfans]

If you are sure that none of the external components are leaking, it must be internals. Possibilities include ( but not limited to ) : 

Reed valve of the first or second stage. This video is about the second stage : 

https://www.youtube.com/watch?v=a7T_4zrgXnc&feature=youtu.be



Internal check valve : 

https://www.youtube.com/watch?v=YjsBcKSVeGk&t=385s



Others have reported 2nd stage piston rings. The pressure problem and high temperature issue vanished after they are replaced. If I were you, I will tear the head down and clean the reed valves, check the check valve O rings and replace the second stage piston rings. 

 

[Smitty911]

Just ordered one of these, should be here in a week.

First order of business is to clean it out, I've seen videos of metal shavings left in hole and other little things.

Smitty

 

[cajun1.]

Is there anything else holding it on other than the four Allen bolts?