ok today my dad and i changed my bypass hose for the anti-frezze... finaly got the hose off .... the got the new one on.... well i was letting it run i went upstairs to change clothes came back down stairs heard this horrible noise opended my front door theres my truck overheating and smoking so bad i could bearly see to get in the door to turn it off.... my dad sayed he checked on it like 3 mins befor and thats when he closed the hood....dose anyone have any idea what could had caused this! it kind of looked like something exploded with the antifrezze on the right side where the coolent and windshiled tanks are... oh this is an 88 bronco... we checheked the work we did and everything seemed fine!... anyone have any ideas?

 

most times when you replace any sort of coolant hose you need tomake sure that coolant is in the hose and the radiator hasnt drained below the level of the pump cuz if it has it will not start pumping fluid on its own it needs to be started (i.e. have fluid in thepump to start the pumping cycle) so when you guys did this i imagine it drained below the pump at one point and when you filled it back up you needed to hand squize the lower radior hose to pull fluid into it so it can start, but didnt. i had this hapopen tomy old camaro and after about 10 minutes of runnin i came out and the head gasket had blown and a frieze plug and blown out. tore the motor a new one.

 

i think it might be the thermostat

 

My money is on air in the cooling system.

 

sounds like it was "air-bound" Next time let the engine run for a while with the cap off, the coolant will rise in the radiator, maybe overflow, then when the stat opens the coolant level will drop as it circulates. Run the heater to make sure there is circulation, refill and replace the cap.

 

Had the same thing in my car, just took about 7-8 minutes. It was air in the system.