@newell-post said in This is strange.:
BTW, if something blocks air when valves are not depressed, how do you know for sure it is the third valve? Does the horn block air with the third valve up and pass air OK with the third valve down? That would be really weird.
The third is definitely the one in question. At least that is what seems the most logical since that is that one that changes things when depressed. The other two were just fine.