i have a bypass valve... i've heard it used once... i hit a real big puddle and all i could hear was a vaccum under the hood... i checked my filter and it was drenched... i don't know how it could have gotten that wet... i'm glad i have it... it's saved me once already...

whenever i want to make sure i have the horses i have a sillicon hose that i can put in instead of the valve...

but then of course i live on guam where it rains all the time...