Wow. I must say I am impressed this actually worked. I had a leak on my Impact...and I believe it is because the 9x1.5 o-ring (C39 on schematic; sits by regulator housing) isn’t sealing properly. Then the man, the myth, the legend came in and told me I should use engine/transmission oil stop stop leak to swell the o-ring....and it worked! As you can see, the top o-ring (and the left one where they are placed horizontally) has gained more width through osmosis....crazy stuff. It isn’t as visible on camera, but it is very noticeable in person. Thanks Odoyle. Now, I hope this stupid impact will seal.