Yong Heng Replacement Parts?



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Offline Mondo

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Re: Yong Heng Replacement Parts?
« Reply #40 on: June 08, 2018, 03:15:55 AM »
Yep,

That's a complete head. first stage piston, rings, second stage piston/seals, the whole top end. Simply remove the end of the stainless lines that connect to the compressor and the two bolts that attach the first stage head, slip the whole head off. It does help if the crank shaft is at the top of its stroke when removing the lower connecting rod end.

The new head, even included the paper gasket.

I changed the head on mine because I was worried about oil blow by on the first stage piston rings. I had about 10 hours of run on it. its wasn't really bad, just bad enough to worry me. The complete, new head went on without issue. I seated the rings for about 10 minutes at zero load. changed the oil. I have about 3 hours on the new head, very little, what I would consider a normal amount of oil blow by still.

I took a set of first stage piston rings and second stage seals, rebuilt my original head and have it boxed up ready to go when needed.

BTW, the yong heng uses a one piece, second stage seal with an O ring under it. Luckily, I had installed similar seals before. install the 3 O rings on the piston. Then, put the seals in HOT water, let them get a little soft and pliable. Used a small set of needle nose pliers to stretch them just a tiny bit, enough that they would slip on the piston without any damage. If you're not careful, you'll ruin a seal before you get it on the piston. Go slow, don't force them on the piston.

Once the seals are on the piston, it does not want to go into the bore. I again heated the seals(and piston) in HOT water. Worked them a bit with my fingers to conform them to the piston. Then shocked them in ice water, letting them completely cool. Now, they JUST slipped into the head. Again, go slow, a little wiggling/working of the piston will get the seals in without damage.

The first stage rings are easy. just be careful you don't snap a ring as they are hard and brittle. I did break the used middle ring removing it from the piston...

The seals are a non split type, but there is no need to do the above process, that is because the second stage seal head screws off to replace the seals.
I suspect this might be the cause of a failure in some pumps as the seal head comes loose and screws out hitting the head.
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Online jab

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Re: Yong Heng Replacement Parts?
« Reply #41 on: June 08, 2018, 05:09:30 PM »
Does  anyone know  what the torque is  on these  bolts/cap screws ?  we came up with  40 lbs.  by checking the torque  to break them loose.  This pump we are still testing out.  has not been ran under  a load
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Offline hunter457

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Re: Yong Heng Replacement Parts?
« Reply #42 on: June 28, 2018, 07:29:25 PM »
 8) seeking stator windings
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Offline sykocis

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Re: Yong Heng Replacement Parts?
« Reply #43 on: July 23, 2018, 10:16:03 PM »
Does anyone have a guess as to what part would be needed to repair the mophorn compressor with a crankcase cover that exploded? 
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Offline Harpoon1

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Re: Yong Heng Replacement Parts?
« Reply #44 on: July 24, 2018, 01:21:14 PM »
Does anyone have a guess as to what part would be needed to repair the mophorn compressor with a crankcase cover that exploded?

Wow!

Tell us more.....when.....how....what psi.......please!
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Offline cosmic

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Re: Yong Heng Replacement Parts?
« Reply #46 on: July 24, 2018, 01:57:12 PM »
looks likely dropped on front of it.. no real pressure in crankcase.. the oil breather would go first.. check piston for holes or cracks...
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Offline cosmic

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Wade on in the water ain't deep !! "DANG" IT IS DEEP !!!

Offline sykocis

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Re: Yong Heng Replacement Parts?
« Reply #48 on: July 24, 2018, 04:49:35 PM »
Was filling the cylinder for my Bullboss.  It stopped filling at 40 Bar.  Then - BOOM!!!  Found part of the case cover lodged in my garage door.  Found the breather in-between the radiator and bumper of my SUV.  I'm not really sure what happened.  Some fluke accident.  Maybe a clogged breather.  Maybe a seal failed and there was back-pressure going back in to the crankcase.  I'm just happy to be uninjured, seeing as how that piece of metal that was lodged in the garage door came flying by, fairly close to my head.  I'll need to pull the compressor down and inspect it to find the failure.   Anyway, thank you guys for the links.
« Last Edit: July 24, 2018, 04:52:05 PM by sykocis »
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Offline prfssrlee

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Re: Yong Heng Replacement Parts?
« Reply #49 on: July 24, 2018, 09:42:04 PM »
40 bar is only 580 psi. IMO, that wouldn't be enough to blow out the crank case which normally operates between atmospheric and 150-200 psi. I've had mine up as high as 350 psi when trying out the booster pump concept (yeah, don't run it that high). There must have been a defect in it or the screws failed or something (maybe the threads were improperly tapped?). The breather is plastic so its threads would give way at a pressure far below what was needed to blow up the crankcase (again, unless it was somehow defective). And I gotta believe the same goes for back-pressure going into the crankcase - it would blow out the plastic breather by design.

Must have been an amazingly scary moment - glad you're okay.
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Offline prfssrlee

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Re: Yong Heng Replacement Parts?
« Reply #50 on: July 24, 2018, 09:44:10 PM »
just looke more closely are your (frightening) photo. I'm guessing a casting defect? The screws did not fail since they are still there holding what's left of the crankcase. And the breather did not blow out either. Yowza.
  • Wenham, MA. USA.

Offline sykocis

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Re: Yong Heng Replacement Parts?
« Reply #51 on: July 24, 2018, 09:59:09 PM »
I put the breather back in after I found it.  Thatís why it was in the picture.  Like I said before,  Iím chalking it up to freak accident that probably I would never happen again.  Definitely once in a lifetime lol.  Iíd guess casting defect.  Iím debating on if I want to rebuild it or, if I should save some pennies and get a more expensive and well made pump.  Iím confident if I rebuilt the thing, it would work without issue but, understandably, Iím a bit shaken.  Regardless,  I made it out with ten fingers and, ten toes.  My hand pump came in today and my cylinder pumped up.  Itís time again to put pellets to paper my friends.  Thank you all for the advice and the concern.  Thatís why I have come to love the community here.
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Offline sykocis

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Re: Yong Heng Replacement Parts?
« Reply #52 on: September 07, 2018, 10:11:03 PM »
Back again after some time.  So, the replacement parts for the comprebfinally arrived from China today.  I ordered the parts over a month ago.  Oh well.  So I start the process of tearing down the compressor.  I begin unscrewing the tube fittings on the left hand side of the compressor (brass block, donít know what itís called).  I noticed a brass part with threads laying in it loose.  I dump it out and it looks like some type of filter.  Regardless, I came loose, probably due to vibration.  I also notice some case screws laying under the motor.  So I start blowing air in the top of the brass block on the right hand side of the compressor with my mouth.  No air comes out the outlet side.  Iím working on pulling it apart now.  Maybe there was more to the front casing exploding than I first thought.  Iíve heard that you should pull them down once you receive them from wherever you order them from, and check everything.  That was my mistake.  I jumped the gun and just for it.  Iíve learned my lesson.  Hopefully, I can get her operating without issue.  Fingers crossed.
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Offline Csexton

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Re: Yong Heng Replacement Parts?
« Reply #53 on: October 14, 2018, 09:14:52 PM »
I ordered many parts from AliExpress. It took about 2 weeks to arrive.
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Offline hunter457

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Re: Yong Heng Replacement Parts?
« Reply #54 on: October 16, 2018, 01:20:34 PM »
I just bought another new compressor, plenty of spare parts now lol
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Offline PaulT58

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Re: Yong Heng Replacement Parts?
« Reply #55 on: October 16, 2018, 03:17:29 PM »
If anyone else is interested, I found this digital thermometer on Amazon for $6.99.  It displays Fahrenheit instead of Celsius.  The specs say it will read from -58F to 199F.   The max operating temp of the YH is 65C which converts to 149F, so this should work...  It is the same size as the digital thermometer that comes with the YH Compressor.

https://www.amazon.com/gp/product/B073RP1476/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

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Offline Voltar1

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Re: Yong Heng Replacement Parts?
« Reply #56 on: October 22, 2018, 02:08:04 PM »
For the lad with oil coming out breather. These compressors are splash lubricated and to prevent oil getting to the breather the rubber cover gasket is also a 'dam' to keep the violently splashing oil going where it shouldnt. Do not remove that rubber gasket.
If you need to add some sealant use a smear of Loctite gasket maker or equivalent.
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Walter

Offline Voltar1

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Re: Yong Heng Replacement Parts?
« Reply #57 on: October 25, 2018, 10:12:19 PM »
just looke more closely are your (frightening) photo. I'm guessing a casting defect? The screws did not fail since they are still there holding what's left of the crankcase. And the breather did not blow out either. Yowza.
Curious where you get your information wrt the case seeing anywhere close to 100psi? 580psi on that case? Darwin award that is. Casting defect? Designed for atmospheric and blows out at likely 100s psi above that and that os a casting defect? Sorry man but bad info you be giving folks.
  • Rocky Mtn House, Alberta
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