I have made several attempts to burp the cooling system in my truck because it had luke warm heat. I think I tried like 4 times before.It would take maybe 1/4 gallon each time but wouldn't help my heat isue.This morning I thought I would try again.I took off the rad cap and started the truck.It ran for about 15 minutes. I ran in the house to get something.I was inside for about a minute.When I cam out there was alot of antifreeze about 2 feet in front of the truck and the overflow was full.I shut off the truck looked for leaks but couldn't find any. So I decided to refill the rad.This time it took about a gallon.It runs fine doesnt overheat and my heat seems to be better but it's hard to tell because it's 51 deg here today.

So it seems that the burping was successful this time but is it normal for it to shoot antifreeze out the rad cap like that?

 

I've seen that in lots of vehicles over the years. The bubble was moving fast, pushing coolant ahead of it on its way to the atmosphere -- like when a burp is trying to escape past that column of beer you're chugging. No worries.