thermostat

[CAE79]

How can you tell if a thermostat is stuck closed without removing it, and how can you tell if it opens. 1985, 351.

 

[steechfinger]

ur bronco would be over heating but dont wast ur time just go buy a new one there only 10 bucks and its easy to change

 

[bidibronco]

Start the truck with the radiator cap off, if the water is being cerculated then it's open, if after warming up it's still not cerculating, it's closed. If I remember correctly, the Bronco's thermistat is a 190? But that should give you an idea of what it's doing. But don't take off the cap if the motor is hot or you get splashed!

 

[whitey]

i would recommend replacing the water outlet housing at the same time. they're cheap. a lot of times over the years they start to corrode and if you take it off and it is, you're kinda stuck or have to go trough the hassle of putting it back together unless you have another ride. besides peace of mind is worth the $20something you'll spend on the housing.

 

[snowman74]

Yep! It would overheat if it were not working. The purpose of the thermostat is to stay closed until the coolant temperature reaches a certain degree (190, 180, 160, whatever). When it opens, it allows the coolant to circulate through the radiator so that it can be cooled while the coolant in the radiator goes into the engine to replace the hotter coolant. Put on some gloves, don't get near the fan, when the engine is hot and running, you should feel flowing through the upper radiator hose. Be careful...it's going to be hot.

Snowman74 >-