Burping the cooling system?

[I_luv_HP&trq]

I may have to change out a radiator for someone and I always hear about people "burping" the system. Is this just to get unwanted air out or something? Anyone know how necessary it is or how it's done?
thanks for any info.

[MonteCitan]

some vehicles have bleeder screws (GMs.. mostly).. most vehicles don't need too much..

for my stang(s) I loosen up one of the highest coolant lines (usually a TB line) then run the car til coolant starts coming out of line... hook line up and keep refilling the overflow til it gets to mark.. (or in case of the non-degas bottle style IE older stangs.. fill radiator directly...)then wait for tstat to open, refill again, close cap, check level, then check for leaks.. should be good from there

hope I didn't confuse you..

[DarkShadow]

It removes air from your cooling system, and yes it is necessary. You don't want excess air pressure causing improper coolant flow.

You can burp it by opening it up at the highest point in the system. Luckily ours is easy to get to. It is the largish bolt that is in front of the intake manifold and above the water pump with black tubes leading up to it. Just open it up and let coolant start coming out, close it back and refill from your cap. It will relieve pressure, if any, and cause less of a air pocket. There will still be some air obviously, but it will be less pressure is the key.