how do you get air out of cooling system?

[J B Cuz]

I put in a new to me engine and now when I run it the temp gauge pegs after a short run time. I have put in a new radiator, hoses, t stat, and a heater diverter. I have read in some posts about air trapped in the system, and think that is my problem. How do you get it out?

 

J B Cuz

[maddzz1]

Remove the temp sensor at the back of the engine on the drivers side. DON'T do it with the truck running. The front of the truck should be down hill if you can. don't pull it all the way out, just enough for the air to come out. When coolant comes out just screw it back in.

[sinkrun]

Do not try this with hot coolant yes I did this. :doh:

[Eagle]

Do not try this with hot coolant yes I did this. :doh:

Has your hand recovered yet?

[64 Cheyenne]

On my friends Renix, he put a HO style Tstat housing with a radiator petcock in it to "burp" the system.

Just crack the valve when filling, maybe do it again after a short run. simple.

[rtyler8140]

I did a slightly different method when I changed my water pump. I just left the cap off of the overflow tank and then squeezed on my hoses several times with a pretty good amount of force and watched the air bubble out of the overflow. Keep pumping until you get no more bubbles.

[J B Cuz]

I found out the problem. The free motor I put in was from a 90 wrangler. It used the belt system and the MJ uses serpentine. The change also affects the direction the water pump rotates. I installed the reverse rotation pump and it works great. So, after spending all the money I know my cooling system is all up to par.

 

J B Cuz