Tip: Fuel drain warning

jlfernan · #1 08-24-2006, 01:01 PM

There I was this morning just doing some detail things to kill time while I wait for some parts. I decided to install the fuel drain on my left wing. I put some fuel lube on the threads and started screwing it in. It went about four turns and stopped. Fearing I had it crossed threaded, I pulled it out and verified the the threads in the valve and the fitting were fine. I put a little oil on the valve but still no luck. The drawing shows the fuel drain flush with the fitting. I couldn't find anything in the directions. I measured the valve and saw it was a tapered fitting. Before I grabbed a bigger wrecnh, I called Vans. They said, "Oh yea, the drain only goes in three to four turns, that's an error on the drawings". Good thing I didn't grab that bigger wrench. I can't imagine the havoc I would've created if I had followed the drawing. For those of you coming up to this part, the drain sticks out, about 5/8th's of an inch of threads showing. Torque to about 70 in lbs and you should be all set.

N523RV · #2 08-24-2006, 01:04 PM

I tapped mine out a little bit to get it to screw in farther. It isn't flush but much better than the 3 turns you get.

Radomir · #3 08-24-2006, 01:18 PM

I managed to get mine all the way in. However, after seeing a few RVs, it's different on just about every one of them.. some have it close to all the way, others are not quite as much in.. etc.. Bottom line is.. it needs to go in as far as it can and it doesn't leak.

RV7Factory · #4 08-24-2006, 01:52 PM

Perfect timing on this post (for me), thanks Jorge.

John_RV4 · #5 08-24-2006, 03:01 PM

Perfect timing for me too. I have to replace one that is 17 years old. Keep that in mind when you reach for that bigger wrench :-)....

John

vmirv8bldr · #6 08-25-2006, 10:05 AM

It's best to do at least a test fit with the tank baffle still off. Remember, you want this drain to be at the low point. If the threaded portion sticks up inside your fuel tank, it's no longer a sump and you continue to accumulate a good bit of unwanted material and water in the tank. With the baffle off, you can do a test fit and visually ensure that the end of the drain is still below the level of the skin.

These are low-wing planes. This is not a readily visible item and I doubt the drain valve sticks out far enough to significantly slow anyone down. Fuel lube it, and put it in to the proper torque and forget about it. Form follows function here.

flydjd · #7 08-26-2006, 06:13 AM

Also good timing as I had noticed the same problem when I screwed my drains into my QB Tanks.....but not for the final time so my Q relates to proseal...have people used this for the final fitting of their drains ? (Obviously whilst making sure that they don't block the drains

)

Kyle Boatright · #8 08-26-2006, 07:10 AM

Don't use proseal on your fuel drains. The fittings are tapered and will seal themselves. You might put a little fuel lube on them so you don't get galling between the drain and the fitting in the wing.

Putting proseal on them will make them harder to remove (and you will need to remove them at some time, if only to replace the little "O" ring inside). In addition, if you use proseal, then remove and reattach the drains, you're running a real risk of knocking some proseal loose and having trash in your fuel.

flydjd · #9 08-27-2006, 03:25 AM

Quote:

Originally Posted by Kyle Boatright

Don't use proseal on your fuel drains. The fittings are tapered and will seal themselves. You might put a little fuel lube on them so you don't get galling between the drain and the fitting in the wing.

Putting proseal on them will make them harder to remove (and you will need to remove them at some time, if only to replace the little "O" ring inside). In addition, if you use proseal, then remove and reattach the drains, you're running a real risk of knocking some proseal loose and having trash in your fuel.

Kyle that is all noted, thanks for the info

Best regards

David

briand · #10 09-05-2006, 04:35 PM

OK it appears I'm having trouble getting my drain threads to seal. Can I use teflon tape? Is there a suitable product that I can pick up locally? I pressurized my tank and the only place I see bubbles is around these threads. I torqued the fitting to 70"-lbs which helped but I still have a small leak.