Just checking to be sure I’m thinking along the correct path. My 88 Mitsubishi pickup finally stranded me this morning. Been waiting for that to happen.
I replaced the lower radiator hose last weekend because it had a small leak in it. At the time I noticed that the reservoir tank cap had come off, but I failed to think much of it.
This morning I went over bumpy railroad tracks and instantly got big clouds of steam. It’s one of the heater hoses. Large leak because coolant is everywhere. Thing is, they’re only a couple of years old and still in great shape. It looks like the coolant leaked past the joint rather than from a hole in the hose.
And the reservoir cap came off with enough force to pull the dip tube completely out of the bottle. So clearly I have an overpressurization problem.
It could be a HG leak, but the coolant that drained out when I did the hose last weekend was perfect - absolutely no sign of anything in there that shouldn’t be, and I don’t have anything suspicious coming out of the exhaust.
I’m thinking replace the radiator cap and thermostat because one of them is probably sticking - most likely the cap, but the thermostat is cheap and easy - as well as the hoses just in case.
I’m pretty sure I’m on the right track but want validation!