Radiator issues... please help.

I put in a "heavy duty" radiator in my 2005 4.7 liter double cab toyota tundra & now it occasionally starts to overheat because I have to keep putting fluid in it.
Any ideas as to what could be the problem?

 

Overheat + Keep having to put fluid in it.

I see those two things and have to ask:

• Is there any smoke in your exhaust?
• How did you go about refilling coolant after, and which color coolant did you use?

My 1st two thoughts are (A) you may have an air bubble in the works, and as bubbles have come out, you're needing to refill. Or (B) you've got a cracked head gasket, and you're losing coolant in the combustion process.

Either would cause an overheat condition. You may've also dislodged something that's got the t-stat stuck, or if you used the wrong coolant, like yellow instead of red, or mixed coolant, like it had yellow and you added the correct red after, reactions of the two mixing can gum up stuff. Both those two are way more far fetched then the other two bullets above.

Be careful, excessive overheats will crack gaskets and/or blocks.

 

I’m going with option A as @shifty` elaborated upon being the most likely candidate.

 

My question is, why did it need the new radiator in the first place…

 

'Shifty' thank you. Very good info. I appreciate the help.
I used the correct (pink) fluid.
There's no smoke in my exhaust so, I'm hoping that it's an 'easy' fix like just replacing the thermostat.
I have had to add fluid 3 times over the last month & a half...
The AZ. heat isn't helpin much either. lol
One concern I have is that there seems to be an awful lot of pressure... I replaced the hoses w/ the radiator & the upper hose has expanded in diameter & looks as if it could just blow apart.
What would be some signs/symptoms of a cracked head gasket, to look for? I have noticed that I seem to be getting poorer gas mileage... not sure if it's related to this or if I've got something else goin on.

 

New OEM cap too, right?

 

That part above leads me to believe there is air in the system. When the truck is cold, jack the front end up and remove the cap to burp the system. My other thought would be that the thermostat is stuck, or has the jiggle valve in the wrong direction (not sure what the correct orientation is) but it doesn't sound like you messed with the thermostat.
Burp the system but having the radiator cap off, front of the truck elevated (use a jack or park on slight hill) and crank the truck with the heater cranking on high and wait for the truck to get up to operating temp. You might have some fluid overflow from the radiator so be prepared for that.

 

Last time I saw a swollen hose, the engine was severely overheated. Yikes.

 

Where is the fluid going? Do you see it leaking from somewhere?

 

Ditto. High pressure hose is a big one.

Ditto on this also, but I would hope to hell OP would've actually told us if he replaced something else critical to cooling like this.

 

Failing water pump ??? Thermostat not opening up maybe ??? Swollen hose ?? There she blows...hope not.....

If you are adding fluid, then I would be checking for leaks everywhere......