My truck is blowing coolant out of the overview tank and has no heat. Could this be a rad cap issue or head gasket?

Yes and Yes. It could be a simple as a weak radiator cap, allowing pressure release too soon. Then if it is a head gasket, the same thing will happen if it is blown out between combustion chamber and water jacket, it will blow pressure in to cooling system. But then think water pump, or thermostat stuck closed... if it's not circulating = no heat to heater core and overheating engine

It is circulating, I pulled the top hose and it is flowing through the motor.

Ok, then back to your first thoughts. Water pump/thermostat was speculation. Try a new cap, not an expensive try, also with engine running and rad cap off, hopefully you will not see bubbles, because that is an indication ..not proof, but evidence of head gasket

When I start refilling the radiator they are some bubbles initially but they go away as I add coolant. I can let the truck run after I top off the coolant and the level will go down slowly the longer the truck idles.

To state the obvious, it's gotta be going somewhere... that combined with it blowing out cap if under pressure, leaning more and more to head gasket..but I need to be careful and not jump to that either. You know what my next move would be? Rhetorical sorry..get a pressure tester, and with engine cold pump air in and see if you can tell anything..before ripping head(s) off.

And make sure your engine oil looks good..not like a chocolate shake and overfull, or white emulsion on dipstick or filler cap

I'll try the pressure test, hadn't thought about that. Oil looks good, needs to be changed but was going to wait until I corrected the coolant issue to do it.

Good luck....don't know what else to say

I second that radiator cap

Tried radiator cap and now I'm getting small bubbles in the coolant if it's idling without the cap. I'm thinking blown head gasket now.

What happen's if i put anti freeze with soap in my cooling system?

Don't use soap, use leak detection dye. You will need a black light to see it though.

im leaking coolant out of overview tank n i got heat n i replaced my radiater thermostat n water pump..and radiator cap so need help with problem. thought i had to much coolant in it for warm days

I have a 97 f150 with a v6 keep losing coolant out the top of the radiator it has a new water pump that's the only spot that showed a leak

Take your radiator cap off (when cold), start your engine and rev it. Does coolant come out of your radiator when you do? If so you have a blow head.