Ford 850 gas valve leaking

So I have to turn the gas on to my tractor with a screwdriver, theres a supply petcock directly under that gas tank, lately its been forming a drip after I turn it on, maybe like a drip every 30 seconds. Now clearly this is not good but Im in a very rural area and I wanna get some damn work done so Im not sure how long before I get that part. Im not that familiar with tractors, Will the engine get hot enough to auto ignite the gas? Its between 70 and 80 here during the day. Is this how tractors catch on fire,?
I know it needs to be fixed but can I get some work done in the meantime, thats my question

I assume you tried tightening the packing nut?

If it's bottomed out and the stem is still loose, take the nut off, wrap something around the stem. It can be some twisted teflon tape, string, even a strip of strings off a rag, just something to push the packing down tight enough to stop the leak.

Best keep the original valve as long as possible, the new ones are not the same quality.

The engine heat is not the problem, as the leaking gasoline will immediately evaporate once the engine is hot. You're more likely have a fire when the engine is cool, as you have four ignition sources directly below the fuel tank, namely the spark plug wires.

Drain the tank, remove the valve and rebuild it using o-rings from your local hardware store. One o-ring seals the valve screw, and the other seals between the tank and valve. Replace them both. There are plenty of posts on the Ford board that describe how to do this. Here is one: <a href=https://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=ford&th=551799>https://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=ford&th=551799</a>

One suggestion I have is to not drill out the pin that retains the valve screw as described in the above thread. Instead, find a pair of very sharp FLUSH-CUTTING diagonal cutting pliers and grab the head of the pin. This is much easier than drilling and tapping. although it can be difficult to find flush-cutting pliers. The <a href=https://aircraft-tool.com/shop/detail.aspx?id=HT2>ones I use are intended to cut the stems of CherryMax rivets</a>.

Thanks, would you or anyone happen to already know the O-ring sizes?, Sadly whenever I go to the local hardware store which is miles away, they have a million O-rings, none of which are the size that I want

I dont think this is the original, I tried unscrewing the screw which turns it on and off and I was able to back it out some but then it just seems to spin, it could be in some sort of Tight Oh ring but what anybody have some guidance here, Im thinking that it is leaking from the screw

This post was edited by rockwind1 on 05/30/2022 at 10:03 am.

Nice post here that will fill the voids.

https://forums.yesterdaystractors.com/viewtopic.php?t=1474661&amp;highlight=oring

there is no packing nut, just a brass screw head,, looking at pics on line, there is a pin inside the valve that stops the screw when openinging,, i think i am going to break it hopefully,, then i can remove screw, replace the oring on the end and then screw back in,, then i will just have to remember where to stop the screw when opening

I made this adapter for my Ford. Did away with the leaking China valve.

Nice. Here is mine.

If you have the usual valve no need to break a pin. There is a stop rivet that can be pried out, if you have diagonal cutters with flush cutting surface that's a good way to get it started. You can put the rivet back in after you replace the O-ring on the stem and screw the stem back in.

> Thanks, would you or anyone happen to already know the O-ring sizes?, Sadly whenever I go to the local hardware store which is miles away, they have a million O-rings, none of which are the size that I want

If you're thinking you can pull the screw out real quick and swap out the o-ring without draining the tank, that's probably not possible. You have to remove the pin that stops the screw from coming out, and it's difficult if not impossible to do this while the valve is installed on the tank. (I haven't tried pulling the pin out with flush cutters while the valve is on the tractor, but if I did I'd probable drop it and lose it.) Take the disassembled valve to the hardware store and find what fits.

There may be some posts in the archives that give the dimensions of the o-rings; I haven't looked.

> I dont think this is the original, I tried unscrewing the screw which turns it on and off and I was able to back it out some but then it just seems to spin, it could be in some sort of Tight Oh ring but what anybody have some guidance here, Im thinking that it is leaking from the screw

It sounds like the original or a similar replacement. You have to get out that pin that stops the screw from coming out.

It's easy enough to tell if it's leaking at the screw: If you close the valve and it stops leaking, it's most likely the screw. If it keeps leaking when the screw is closed, then the o-ring between the tank and valve is bad.

> Nice. Here is mine.

See that little bump at the bottom of the valve? That's the head of the pin that retains the screw.

It looks like the valve has been replaced at least once. It's too shiny to be original.

i sprayed it with brake cleaner to see it better