Originally Posted by
CliffordK
What is wrong with the pump? Sometimes it is as simple as greasing the plunger, although I'e also broken pump heads, or worn out parts.
My son cracked the body of it.
Anyway, I think I found the culprits, VALVE CORES!!!! The cores in the Schrade valves, the one in the front wheel was loose as I had suspected, and the back tire just had a straight bad valve core, I replaced it with a spare I had and no more hissing air under pressure.