[gsodonis]

I have been running my PWR rad for about 6 months or so without any real issues - except for one. When my coolant reaches temperature and the cap's plunger opens to allow for the expansion tank to fill, coolant leaks out past the cap-to-filler neck gasket. My loss is minimal (4 - 10 oz/week), but I hate smelling that sweet coolant smell when I get out of the car. I have no leaks anywhere else - just at the cap; whatever coolant leaks ends up evaporating from dripping across the top of the hot rad.

I suspect that the threaded nipple (at the filler neck) that holds the expansion tank hose is of insufficient diameter, impeding flow of warm coolant to the expansion tank. The sealing surface for the cap gasket is really thin and the expanding coolant leaks past it. The thin gasket is also letting air get sucked in as it cools - the expansion tank stays pretty full, but the radiator header has a air gap at the top of a few ounces.

Does anyone else have this problem with the PWR rad? If so, what are the fixes? Bore out the hose nipple? New cap (non PWR supplied)? Double up on the cap-to-filler neck gasket material?

Any and all help is appreciated.