Not having too much luck with the family fleet these last two weeks. Last week it was the wife's 2012 Traverse AC system; this week it's the daughter's 2005 Highlander with a leaking rear valve (right side of engine) gasket. The thing started leaking pretty heavily within just a few weeks and got progressively worse. So I had to pull the the rear cover. It's not an easy job. It took me almost seven hours to finish everything up and clean the rear of the engine of grime and oil.
The gasket and tube seals were toast. Everything was hard and brittle. Considering that this gasket has never been changed, it's a miracle that it lasted this long. Kudos to Toyota for that small favor. That said, replacing this gasket is a true PITA because of the rearward tilt and slope of the right cylinder head. Without a good set of 1/4" drive tools and swivel sockets, this job would have been a true mess.