When i installed this cap on my torpedo heater the heater itself started leaking fuel on warmer days. After comparing the old cap to the new one i discovered that there are two vent/breather holes in the old one that were not in the new cap. The impressions are there, but no holes. One hole on the top & one on the bottom. I drilled my own holes and the problem is solved. I hope this helps others with the same issue.