In another thread someone observed that you can used a Motive power bleeder to check for leaks in your coolant system since the cap thread and pitch on brake fluid reservoir and coolant expansion tank are the same. I have a very slow coolant leak that I would like to isolate, so I tried this. It didn't work in that I could not achieve any pressure in the coolant expansion tank. I know the Motive works since I am easily able to obtain pressure in the brake fluid reservoir. Is the simple answer here that -yes I have a coolant leak - or am I doing something wrong?