intermittent fuel level indication

[Jake14]

I had the right tank float (standard Van's) level indicator fail at the worst possible time: during a 2.5 hour IFR proficiency flight. The indicator on the AFS 5500 was stuck at 15+ gallons and I was so preoccupied that it never occurred to me to question the reading and I almost ran the tank dry...scary.

The failure is intermittent, it jumps back and forth randomly between the accurate reading and showing full. I checked the ground and added an extra star washer on the mounting bolts. No luck. Seems that if the float was sticking at the top it wouldn't go back to a 'full' reading after showing say, 6 gallons.

Wondering what to check next and whether anyone has seen the same thing on Van's float indicators

[mulde35d]

I haven?t seen the same problem, but having recently done the fuel tanks I remember that during their travel from top to bottom the float came extremely close to the second rib web about midway down. If it shows full after a fill up and stops again at 15 I would probably check for contact with the rib web in the tank.

Just a possibility.

[Gary7A]

My left tank quantity (Van's float) worked well during tank calibration.
Since flights started it has read only zero. I'm assuming a stuck float,
but won't know until the annual when it will come apart. I'm anxious to
hear if you find a solution.


Gary K
RV-7A
Ohio

[mturnerb]

I replaced one of these during the build because it was "sticky" - also had to modify the bend of the arm to be sure it cleared the structure in tank. My left one was a bit sticky when I started flying but responded to a little tap or two and since I started flying has been reliable.