Fuel Tank Drain Cock?

I routinely drain my gas tank in the spring and fall in order to rinse out the inevitable debris that accumulates. I'm considering adding a draincock on the tank in order to make the process easier and keep my arms/driveway from getting splashed when I pop the plug out of the bottom.

Any reason to NOT use a draincock on there? Safety wise? I doubt it would ever get caught on anything since its protected by the frame rail etc. but wanted to make sure.

Also... 1/4npt sound right?

Thinking of this as an opton:
https://www.amazon.com/Dorman-61104...-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1

 

I added one. Got so sick of pulling the drain plug, messes and having to reseal. I tee off and the 90 deg outlet on fitting is the hardline to fuel pump. The inline port going straight down has a valve. My tank is the early under seat model so it's already a safety concern anyways. I flush my gas after winter and this makes it easy. I doubt it will ge caught on anything because it's next to the frame and above it. I'm happy with mine. Use permatex thread sealant (white stuff in small tube). Clean threads with acetone before applying and let it dry before adding fuel.

 

I put a small 1/4 turn ball valve in my '56, in place of the drain plug.

I used an elbow and added about 4" of copper tubing so I could conveniently catch the gas. I reckon I can tap it for other uses in an emergency. The assembly is in a well protected position.

That Dorman unit would be difficult to predict where the gas would go, IMHO.

 

Use a 90 degree fitting, ball valve and a plug. Space permitting.

 

Pete, post a pic please when you get a chance.

 

Posted here. My memory was flawed, it is a needle valve, not a ball valve. I just used whatever I had in the parts bucket.

http://www.earlycj5.net/xf_cj5/index.php?threads/142780/#post-1578252

 

Another plus factor. Gas thieves that usually just poke a hole in the tank will have added opportunity for easy access

I'm another that would either use a valve with a threaded outlet and put a plug in it or safety wire the handle so it can not accidentally drain the tank.

 

you probably won't get all of the fuel out of the tank unless you have a small sump at the bottom where you put the drain, but you'll definitely get the majority of it.

The few times I've drained and removed fuel tanks on various vehicles, I've been surprised how clean they have been. Unless your tank is already corroding, I would imagine there wouldn't be much junk in there.

When I got my 58, the entire vehicle looked like it hadn't had any work done to it for 30 years. when I stuck a flashlight down the tank, it looked brand new inside. (was definitely not a new tank)


But still with modern fuels, it's probably best to drain them anyway I guess, since everything in CA has ethanol in it.

 

My tank has an extrusion at the drain connection. Still doesn't mean all the gas will come out, but good enough.

 

Ya I just figured I could cram a small length of rubber tubing up into it when the time came.

That was actually a consideration haha. I can also pilfer from my own tank without dumping the whole thing with this installed.

True. I usually do a few rinses by dumping more gas in the tank and rocking the vehicle to get more crud out. The drain plug outlet sits lower than the rest of the tank by about 1/4 inch so It gets it pretty empty as long as the vehicle is level.

Not exactly sure that the fuel testers are for but those drain valves are interesting! would love to see em in action.

 

They are for pre-flight fuel testing to check for water in your fuel.

 

Similar design purpose on a Jeep tank is served by the "cup" of the fuel drain. Water from condensation will settle in the cup, and opening the drain removes it. This is a good maintenance step.

With alcohol content in modern gasoline the alcohol will allow the water to blend with the fuel.

When they first started producing gasoline with alcohol content there were a lot of two stroke boat outboards ruined because oil won't mix with water, and water was in the fuel due to the alcohol.