Air leaks easier than water so when you fill the system with a 50/50 mixture of water and anti-freeze you should be fine. Don't waste money on an origional plastic bottle. They are way too expensive and will eventually crack and leak. Get a metal header bottle. The best test is to fill with water, pressurize to 15 psi and watch if the level drops. If it does drop then it is going out someplace. Check the oil level, if it is going up then the coolant IS getting past the liner seals. David Teitelbaum vin 10757 --- In dmcnews@xxxxxxxxxxxxxxx, "cruznmd" <racuti1@xxxx> wrote: > A key "moment of truth" during the re-assembly of my engine is the > cooling system pressure test. > > Following Dave Stragand's advice, I hooked up a small pump the the > overflow bottle to pressurize the system. The first thing I note is >