Air Valves

i've had the bliftluft for 3 1/2 years never had problem...only thing that i don't like is that they sound like thier farting when let them out

on the ascos though i have had a few (3 to be exact out of like 50)that had shavings in the diaphrams.2 cleared them selves one actually needed to be taken apart and cleaned out but other than that they have been bulletproof