Bleeding Coolant System

[EquatorHeat00]

When you bleed the air out of the coolant system do you have to have the car running? Also, does the radiator cap have to be off?

When I put a 160 degree thermostat in my car in the spring I just loosened the 1 brass knob closest to the thermostat with the carv running, and the radiator cap off did the other 1 have to be loosened as well? Car never over heats, but I still on occasion loose antifreeze.

Please tell me proper procedure for bleeding the coolant system want to make sure I have no air in the system?

I also dont get very good heat at all noticed that now that its colder outside. Can there still be air in the sytem if the car has never over heated?

[brothapig]

Well, I can tell you what I have done, though it may not be right. Hopefully someone will chime in if I happen to be wrong, or if there is a better way.

I opened up the bleeder screw on the heater core hose before I even put antifreeze in. Then I filled up the radiator until it was full. I then closed all bleeder valves and ran the car until there was a little bit of pressure in the system, and cracked opened the bleeder screw on the thermostat housing until I got a flow of antifreeze (watch out to make sure of it runs on the opti) Then I cracked open the bleeder screw on the heater core hose until I got antifreeze. Before I shut it off, I filled the reservoir up to the "HOT" line on the dipstick. I didn't have any problems with air (although I may have needed to top off the radiator after a couple of days, but only once)

Incidentally, the reason I had to drain my coolant system was because my heater core was plugged; apparently it's a common problem on the F-bodies. That is most likely the reason you have little to no heat. To flush, I simply (well, in theory anyway) removed the inlet and outlet heater core hoses from the water pump/thermostat housing and back flushed it with air/water (not high pressure air). I've done it on my car 3 times now. I would suggest running some coolant system cleaner through your car before you drain (it needs a couple of days to work)

Good luck.

Ryan

[Jeff_in_Atl]

Here is what you need to know.
http://shbox.com/1/4th_gen_tech2.html#radflush