I've had an EVAP leak for many years that threw P0455 & P0456 codes and it annoyed the hell out of me. I tried tracking down the easy leak points like the gas cap and all the EVAP lines but never found anything significant until now. I dropped my gas tank to change my fuel pump and found "moisture" buildup around the driver side rollover valve, which was relieving and exhausting at the same time. I could either try my luck at buying a used tank or try to fix mine so I put my money on myself first.
I couldn't tell exactly where the leak was at the valve so I pressured the tank and used a soapy solution and found a hairline crack right beside the hose port. I didn't get a before pic of the actual crack so I edited the photo with a black line for representation. I couldn't find an adhesive or epoxy that would be a long term gasoline resistant solution so I decided to try plastic welding the crack away. I used a harbor freight plastic welding iron to melt the area of the crack, deep into the valve, without penetrating through it completely. Seemed to hold well so I pressurized the tank and the leak was no longer there and my PCM codes went away.
Just thought I'd share this because I never saw this offered up as a solution and I'm very satisfied. I'll report back on repair longevity once its gone through a hot summer and cold winter.
I couldn't tell exactly where the leak was at the valve so I pressured the tank and used a soapy solution and found a hairline crack right beside the hose port. I didn't get a before pic of the actual crack so I edited the photo with a black line for representation. I couldn't find an adhesive or epoxy that would be a long term gasoline resistant solution so I decided to try plastic welding the crack away. I used a harbor freight plastic welding iron to melt the area of the crack, deep into the valve, without penetrating through it completely. Seemed to hold well so I pressurized the tank and the leak was no longer there and my PCM codes went away.
Just thought I'd share this because I never saw this offered up as a solution and I'm very satisfied. I'll report back on repair longevity once its gone through a hot summer and cold winter.
