On the leaking issue, I am currently using a size 149 buna X-ring seal on the cover. Leakage has been reduced to almost nothing. I noticed there is an open space above the X-ring seat lip and the cover, so I added a second X-ring above the first. The cover seats fine with no additional effort. I could try going one size up on the X-rings. The supplied X-ring looks to be made of silicone or something like it. I suspect the temp rating is off as it tends to seal better cold than hot. Also, I suspect the design of the cover may be suspect as it just looks like an odd arrangement to me.