I have not worked on the gas valve in your older furnace, but this might help.
Bryant RV has many of the older camper appliance service manuals. This site Service Documents and Manuals
Scroll down to "Furnace Service Manuals" then to "Hydroflame FA-72, HF-77, FA-79, DC-82, and AC-82 series service manual- Dated Jan, 1985." It is an 80's series manual. Your HF 80 series model number shows up on the bottom of PDF page 9. Hydroflame changed the model numbers back then and they also changed with future improvements.,
See this service manual. http://bryantrv.com/docs2/docs/hydroflameold2.pdf
Scroll to page PDF page 8 (file page 7), they talk about the pilot adjusting screw with a cover. Look on PDF page 9 (file page
for a drawing of the valve, see if your valve looks like that valve.
My first thought is, there is an O ring on the stem of the adjusting screw, but you stated that was not the case. The cover they talk about, it would need to screw in I "think", does yours have any threads to accept a cover? Someone may have take it off and never put it back.
Finding a new cover is going to be hard. A whole new gas valve maybe. Ebay and others might have the valve. Atwood Mobile who bought the Hydroflame line way back when, went out of business a few years back and sold out to Dometic. I doubt Dometic will be of much help on a furnace as old as yours.
And for sure, get the leak fixed, your concern is valid. That is not good.
Hope this helps
This may help some, but it does not have the depth as the service manual. http://techsupport.pdxrvwholesale.co...ion-Manual.pdf
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