Saville
Well Known Member
RV-8, 152 hours.
So this weekend I was working on my fuel sender/pressure issues when I noticed that fuel was dripping from the left hand tank vent. I was fairly certain that the outboard end of the vent tube was not submerged in gas, but I checked anyway.
When I removed the gas cap it was a little harder to remove than usual and I could hear that sucking sound meaning there was negative air pressure in the tank. The vent end was not submerged in fuel.
QUESTION: Could the vacuum in the tank due to fuel leaking into a loosened tank vent connection on the inside of the tank? I notice that after a while the fuel pressure in the system will drop even if the fuel selector is on OFF. I'm thinking that after the aux pump pressurized=s the fuel lines, and then is turned off, and the selector turned to OFF from LEFT, that the tank vacuum pulls the fuel back into the tank.
I hooked up a flexible hose to the air vent intake and blew through it. I could feel air AND fuel coming out of the end of the vent in the tank.
I knew what this meant....
But just to be sure, I put my ear right on the wing over the vent fitting on the inboard side of the tank and blew through the hose and sure enough I clearly heard lots of bubbles.
The vent fitting on the inside of the tank is loose.
Ok so here's The Plan - comments and criticisms welcome:
1) Remove the gas from the tank.
My plan here is to remove the quick drain and drain the fuel into new, plastic 5 gallon fuel cans. I'll have a grounding wire from the plane into the gas itself in the gas can.
I would like to dump some of the gas into the right hand tank.
Question: I plan on using a funnel to drain the gas into the can as well as pour it into the right hand tank:
What size filter mesh would you recommend?
2) After removing the gas, I'm going to remove the wing/fuselage fairing and see if I can remove the T-708 large access plate. I'm hoping I can get my hand and a wrench into the opening and onto the nut, from underneath the airplane. If I can't, then the tank will have to be removed and the access plate would be removed anyway, so no work lost.
3) Unscrew the vent tube fastener completely, clean things up, screw the fastener back on with, possibly, ProSeal.
4) I've read threads here where people suggest using fasteners other than the AN515-8B8 philips head screws. I liked the one suggestion of the fastener that has both hex head WITH the philips.
Question: Would I need a washer with the hex head?
5) Button up the access plate using only ProSeal or Van's Flamemaster.
I've looked at this thread to get an idea of how things may go:
http://www.vansairforce.com/community/showthread.php?t=126019
All comments and suggestions welcome.
So this weekend I was working on my fuel sender/pressure issues when I noticed that fuel was dripping from the left hand tank vent. I was fairly certain that the outboard end of the vent tube was not submerged in gas, but I checked anyway.
When I removed the gas cap it was a little harder to remove than usual and I could hear that sucking sound meaning there was negative air pressure in the tank. The vent end was not submerged in fuel.
QUESTION: Could the vacuum in the tank due to fuel leaking into a loosened tank vent connection on the inside of the tank? I notice that after a while the fuel pressure in the system will drop even if the fuel selector is on OFF. I'm thinking that after the aux pump pressurized=s the fuel lines, and then is turned off, and the selector turned to OFF from LEFT, that the tank vacuum pulls the fuel back into the tank.
I hooked up a flexible hose to the air vent intake and blew through it. I could feel air AND fuel coming out of the end of the vent in the tank.
I knew what this meant....
But just to be sure, I put my ear right on the wing over the vent fitting on the inboard side of the tank and blew through the hose and sure enough I clearly heard lots of bubbles.
The vent fitting on the inside of the tank is loose.
Ok so here's The Plan - comments and criticisms welcome:
1) Remove the gas from the tank.
My plan here is to remove the quick drain and drain the fuel into new, plastic 5 gallon fuel cans. I'll have a grounding wire from the plane into the gas itself in the gas can.
I would like to dump some of the gas into the right hand tank.
Question: I plan on using a funnel to drain the gas into the can as well as pour it into the right hand tank:
What size filter mesh would you recommend?
2) After removing the gas, I'm going to remove the wing/fuselage fairing and see if I can remove the T-708 large access plate. I'm hoping I can get my hand and a wrench into the opening and onto the nut, from underneath the airplane. If I can't, then the tank will have to be removed and the access plate would be removed anyway, so no work lost.
3) Unscrew the vent tube fastener completely, clean things up, screw the fastener back on with, possibly, ProSeal.
4) I've read threads here where people suggest using fasteners other than the AN515-8B8 philips head screws. I liked the one suggestion of the fastener that has both hex head WITH the philips.
Question: Would I need a washer with the hex head?
5) Button up the access plate using only ProSeal or Van's Flamemaster.
I've looked at this thread to get an idea of how things may go:
http://www.vansairforce.com/community/showthread.php?t=126019
All comments and suggestions welcome.
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