How do I test the water pump?

Well I replaced the thermostate, but the truck still gets hot after 10 mins of driving without the heater on, heater on drives fine. The top of the rad is hot but the bottom is warm. I am not loosing coolant and it is new.
What are your thoughts?

 

If the coolant in the radiator gets hot, more than likely your water pump is working and circulating it.

When I replaced my radiator and water pump, after getting it all back together, it seemed to take FOREVER to get the water to circulate correctly. I think there was an air bubble in there.

Idle the engine with the radiator cap off, and the heater blowing hot and hard. Idle it at like 1500 - 2000 rpms, and put water in your radiator at the same time. Keep doing this until the radiator is full and the water is hot enough to steam. It might take awhile...it did with mine. Once you're satisfied, go drive it and see what happens.

 

oh yeah, and if you put the thermostat in upside down it might not open right...that's what I was told by the guy at autozone, anyway. I didn't have a problem with mine.

 

I did "burp the system" on a steep incline, 2000 rpm filling the rad as needed. Did it for a while and it ran fine for about ten minutes. took it for a test drive but gets hot after 10 miles or so. level hasn't gone down.

 

If I remove the t-state completly then run the truck I should be able to disconnect the upper rad hose and watch coolant run out, as the pump would be full flow ? does this make sense?

 

is you fan clutch working?

 

I just pulled the t-state and ran water though the engine the pump was working fine, the top hose was pumping out the water as I poured it into the rad. I am going to pull the rad and give it a good once over,

How do I tell if the fan is working? it works at start up (LOUD) as usual.

 

UPDATE: I replaced the rad and it seems to be the fix. I took it for a 20 min ride with no heater and it didn't over heat. The other rad must have wieghed double the good one. I thought it was stuck be no just really heavy. I hope this des the trick because a week without wheelin has sucked!!!