The strangest thing happened today... I left my truck idling for a little while (5 minutes or so), noticed the temp got pretty high, to about 220, turned off the engine and looked under the hood. My thermostat housing/water outlet was spraying water out of the side! I've seen these leak from the bolts before when under pressure, but I seem to have just blown a crack in mine, near one of the bolts. I ended up pulling the thermostat out and applying RTV around the crack, inside and out so it wouldn't leak on my way home.
Easy fix, sure... but what would cause this? It's a relatively new thermostat, just a few weeks old. I can't imagine that enough pressure could build up on the radiator side of the thermostat that it springs a leak like this.
My only conclusion is that I weakened the housing last time I put the thermostat in... the first time it didn't set in there correctly, and putting torque on the bolts weakened the casting. After fixing that, it ran fine for several weeks. Anyway, I'm off to get a new housing and gasket. I'll try and post pics of the housing once I pull it off and scrape away the RTV.
Easy fix, sure... but what would cause this? It's a relatively new thermostat, just a few weeks old. I can't imagine that enough pressure could build up on the radiator side of the thermostat that it springs a leak like this.
My only conclusion is that I weakened the housing last time I put the thermostat in... the first time it didn't set in there correctly, and putting torque on the bolts weakened the casting. After fixing that, it ran fine for several weeks. Anyway, I'm off to get a new housing and gasket. I'll try and post pics of the housing once I pull it off and scrape away the RTV.
