[ZL1power69]

Originally Posted by BlazerLT

Yes, you need to replace your rad cap. The stock unit is flawed and won't seal properly which therefore won't hold the 15-16psi needed for the cooling system.

This will allow the coolant to boil off a bit.

Get the vehicle on ramps, start the engine cold with the rad cap off and the heater on full hot and max fan and start adding coolant as the level starts to drop. This will have the rad set as the highest point in the cooling system and therefore air will slowly migrate to that point instead of in your heater core coolant lines.

Once the coolant starts to rise in the rad and start to come out, install the new rad cap and fill the overflow tank to about 3/4s.

With Dexcool, they say to keep the overflow tank topped up and just below the overflow hose line.

Take it for a drive and get it warmed up and then come back and turn the heater to full cool and you might burp some coolant but that is good and means you have all the air out.

i do not recall what lb cap is on the rad but i know for a fact that it is not the stock one. also, i have done the procedure u listed 3 times already and there is still some air in the system (everytime i have to refill the rad, air bubbles to the top of it). i have not touched the overflow in about 3 months because it stays at the same level all the time.