Review on High-Quality Water Hose Fitting Replacement for BMW 335i N54 N53 N52 Engines - 11537541992 11537544638 by Omar Card

Installation is very important. Well designed and made. However, as many others have noted, the O-ring that comes with it is too big. This makes installation almost impossible. The first attempt at installation with lots of "magic grease" resulted in a pinched o-ring and a leak. The leak was discovered immediately upon filling. On the second try, with petroleum jelly and a lot of effort, the o-ring was seated properly with no leaks. The trick was to put the bottom in first and use a plastic cutting tool to push the o-ring down from the top by applying pressure and twisting slightly. This is by no means an easy task. I recommend purchasing the original O-ring before installation to use this product. Note. It was installed on a 2011 E89.