Toyota Repair: Toyota 4 Runner overheating, toyota 4 runner, flow problem

Question
Toyota 94 4 runner v6 is overheating especially on hills on hot days changed radiator already. My service rep said possible flow problem. Is this a water pump issue or thermostat? will change both if needed

Answer
Check your radiator level to ensure it is full.
Try running with the heater on Hot and the fan on Fast. (Roll down windows, tee hee)
If the engine does not overheat, then it is your thermostat.
If the engine overheats anyway, sounds like your water pump may not be working properly.  Check to make sure the drivebelt is not too loose. (Make sure engine is off).  If belt is proper, then check water pump weephole to see if it is leaking.  Look around for other leaks.  Listen for noises from water pump when engine is running. (use a mechanics stethoscope).
Check to see if oil level has unexpectantly gone up; this could indicate water getting into the oil system.

Hope this helps.

Vince