Advice on Fuel Tank Mod 37A to eliminate the sight gauge

[Hairball192]

Hi all,

I'm building an RV-12 ULS... the fuel tank is complete but NOT installed yet. I'm in the process of doing SB 13-12-19 for the tank attach brackets and Mod 37B for the fuel vent.

Mod 37A eliminates the sight gauge and is only required if the sight gauge is leaking. Since mine hasn't held fuel yet I don't know if it'll leak.

My question to the group is advice on whether or not I should just go ahead and do 37A to eliminate the sight gauge preemptively or if I should only do it down the line if mine leaks. Sorry I couldn't attach the pdf's so you'd be able to see it more precisely.

Thanks,
Harry

[mike newall]

Our 2016 12's had the mechanical fuel gauge on the top and we wired the output to the Dynon and calibrated it.

Nothing else.

If you are talking about an extra tube style level gauge - unnecessary.

As many have discussed previously, the mechanical gauge is a great 'Go To' pre flight indicator. It is also accurate to the last drop, which is what you want. Most RV fuel indicators do not show the top 1/3rd of the tank, unless they are capacitance gauges. I know how much I put in by observation or dip stick. What I want in flight is the bottom 1/3rd to be accurate to avoid any embarrassment.

[DHeal]

Harry -- Check your PM. -- DHeal

[Mich48041]

My tank has the original sight gauge and it has never leaked.

[funflying]

Me too Joe. Original sight gauge, Moller on top, and the Skyview quantity calibration at 15 indicated as the top. Other posts have addressed the total indicated limits due to tank and sender geometry.

No leaks since I redid the front inspection plate, and the tank reinforcement mods last year.

[Piper J3]

I have early RV-12 S/N 120058. I kept the side sight gauge. No problems.

A tip on modifying the tank for internal front mounting tabs. Easiest way to do it is to remove the top of the tank, do the work, and then reinstall the tank top. Much better than working through fuel sensor plate.

[RFSchaller]

I finished my 12 in March 2012 and have almost 1000 hours on it. The sight glass has never leaked, but it is useless in my opinion.I would get rid of it if I was building it now.

[DaleB]

Mine was leaking like a sieve when I bought it. Don?t miss it one bit. While I had the tank apart for that and numerous SBs, I installed the Moeller gauge on top. That?s nice to have when you?re filling the tank, or as a quick preflight check.

[Hairball192]

Thanks for the words of wisdom, everyone. This is the first I've heard of the Moeller gauges. Is there a thread where I can find guidance on which of their gauges to use? I'm trying to stick to ELSA for now, but would like to install it after it's certified.

Wish I'd read the advice on removing the top of the tank for the service bulletin sooner... I just finished that job tonight.

Best,
Harry

[Piper J3]

You will want to buy the RV-12 Moeller Gauge directly from Van's. It is correct design for height of tank.