Started my Yong Heng rebuild today......

Jump to latest Follow Reply
Gerry52

Gerry52

Member
Oct 13, 2017
5,774
6,305
Oceanside,California, United States
Those with experience, did you use any gasket sealant when replacing gaskets? WHAT TYPE did you use? Tear down was easy but the person in China who assembled it seems to have used Crazy Glue on the gaskets! Took over an hour to remove all traces of old gaskets. Couldn't figure out why my YH would only pump to 3400psi. Top 1/4" of HP piston separated from the rest. So glad it didn't score my cylinder. Never sounded weird or gave any indication other than not going past 3400psi. 3.5 years with ZERO problems! Lmk about gasket sealant (or any other tips) & THANKS in advance.
Gerry
 
Gerry, when I rebuilt my Hatsan lightning I used this, especially around the water channels-
IMG_5815.png

Your local Napa will have it.

Of course 100% clean and grease free on all areas before applying, and let it fully cure before water gets back in the system.
If rebuilding the piston area with new rings, apply a thin coat of assembly lube like lubriplate on the piston and the inner walls the piston reciprocates in
 
Upvote 0
Yep, top of HP piston and rings bit the dust on mine too. I replaced the whole piston/crank assy. After cleaning off the old gasket material, I did not use any sealant. So far, it's been working better than ever, but I've only been using it to fill rifles directly. I have not filled any tanks. It usually runs 2-5 minutes to fill a gun, which I've done about 30 times so far.
 
Upvote 0
Thanks guys! Didn't have to get into water channels. After further investigation I realized that my HP cylinder DID get scored. Luckily I have a virtually new top cylinder that's pristine. I'm using that one (had a lightly used YH for spare parts) & should be up & running tomorrow, fingers crossed. Have a new piston ass'y, top & bottom, that's been waiting for this day so I think I'm good to go. Guess babying it paid off. For the most part everything looked better than I expected.
 
  • Like
Reactions: WorriedMan
Upvote 0
Bigragu said:
Gerry, when I rebuilt my Hatsan lightning I used this, especially around the water channels-
View attachment 399199
Your local Napa will have it.

Of course 100% clean and grease free on all areas before applying, and let it fully cure before water gets back in the system.
If rebuilding the piston area with new rings, apply a thin coat of assembly lube like lubriplate on the piston and the inner walls the piston reciprocates in
Click to expand...
Was thinking about a VERY light coating of oil on piston rings & hp cylinder. If piston slides in easily maybe not coat cylinder. What d'ya think?
 
  • Like
Reactions: WorriedMan and Long_Gun_Dallas
Upvote 0
I was under the impression that the gaskets (most do) have a sealing layer built into them. During heat cycles, this becomes more and more stuck to the surfaces. Once you pull it apart, it normally tears. I did not use any sealer on my gaskets. I've worked on a lot of engines and see the same thing. No sealant used, but the gaskets look the same when you take them off. Usually split/tear
 
Upvote 0
You must log in or register to reply here.
Top Bottom
Back
Home
Forums
Resources
Menu