New Aluminum Backs

I highly recommend my engine leak test. Using a large syringe, screw the needle valve all the way closed and pressurize the tank with air with a 5 oz. syringe. A small syringe doesn't work for this. Place oil or spray soapy water on the tank to tank back connection and pressurize. You will quickly see the leaks. In addition, this test will also reveal a leak on the case gasket to tank seal. In addition, this same test will also show leaks at the needle valve to backplate and or the threads of the needle valve. One other leak point which is also problematic is where the screws seat in the back of the backplate. Using the same test and nose pointing to the floor backplate up, place oil on the screw heads and note if they start bubbling when pressurized. A tank to tank back seal can be remedied by placing dental floss in the V-groove of the tank. Overlap it ever so slightly. I liberally apply oil filling the groove and then I lay the floss into it, about the 3/4 way around point is when the floss wants to come out just about at the point you feel you were good. I just keep applying oil to is soaking the floss and getting it to stick.