Brief Description: Tank leak test procedure. Part2.
I used the manometer test. Not the baloon test. I bought a 20' roll of 3/8" Inside diameter tubing from Home Depot and cut it in half. Perfect length for this test. I decided to do both tanks at once. The tube goes from the fuel vent fitting, down and bungied tight to the bottom of the coat rack. Then, straight up the coat rack and bungied at the top. The tubes are tight, parallel and straight up the coat rack for each tank. I didn't use color dye in the water. I can see the water level just fine with out it. I used a bike pump to pump up the tank to gain a 2 foot or so vertical difference between the ends of the water.
My hopes were that I could get each tank to the same pressure and then both tank water levels would change in parallel due to temperature and pressure. Temperature and pressure will vary the level up and down about 2 inches. Doing both at once, you should be able tell if a water level change is a leak or temperature/pressure change. If the tank levels don't stay together then its a leak. If the tank levels move up or down in parallel, then its a temp/pressure change.
I had a false leak when Stephanie drove the car into the garage. 45 minutes later the left tank, closest to the car rose 3/4". The right tank went down 1/8". Crap. must have a leak on right tank.
Turns out that opening the garage door cooled down the garage as a whole. Thus the right tank wen't down 1/8". The car was warm and heated up the left tank, so it rose 3/4". 4 hours later the water levels in each tank came back to parallel. Very interesting.
