Green '01

^^^ This.

4x4wolf

Okay so I guess my mechanic can't figure out how to do this, can someone tell me how to burp the system?

jstockert

I have always just loosened the coolant cap. Pretty loose jus not so much it fall off. Drive as normal for about a week. Does the job for me.

4x4wolf

thanks for the tip, does much coolant come out when you do that?

Green '01

I started with a cold engine, loosened the coolant cap, and ran the engine until it got to the normal temp range. While it was warming up and even after it hit normal range, I repeatedly squeezed the top radiator hose (forcing trapped air into radiator and out of hose) until well after I could feel it was full of water instead of half full of water: air evacuated from system.

Carcrazygts2

This trucks burp them selves. Air doesnt get trapped in the upper hose it gets trapped in the heating circuit. How long as it been since a water pump has been replaced?

Green '01

Hmmm. Felt air in upper hose. I could tell by the hose firming up as it filled with water.
I forgot to mention that I did turn on the heat to the highest setting and allowed engine to run until thermostat opened, while keeping an eye on coolant level in overflow tank - filling to "Full Hot" line.

All of this was after replacing intake and hoses.

Manuellabour247

Yes and no. While it's a closed system that is supposed to purge air as it circulates the coolant, there will always be a possibility of air to be in the system. The coolant jackets in the engine aren't machined, they are cast. Which means that there are irregular surfaces that could retain air bubbles.

Will it eventually purge enough air from the system that you won't get fluctuations in the gauge? Yes, but it will take time. Releasing the overflow/reservoir cap is a good start. Make sure you don't lose it. Another idea is to move the heater hoses while it's running to try and force any possible air that is stationary in the hose itself. It shouldn't take that long for the system to purge enough air to function properly with a little help. Good luck.

EDIT** Did you replace the thermostat and water pump?

4x4wolf

Thermostat was replaced, water pump no. Thanks for the tips guys I believe I may have gotten it.

jstockert

You will not lose any coolant.