Question about 1994 GMC Sierra

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I get all cold air / no heat when using defrost and all heaters

Had a new radiator, heater coil etc. replace and now get very limited warmth inside the cab. Fan works wonerfully but no/ very very little warm air is produced. Thank you.

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It is possible that you may have an air lock in the system. You need to drain the rad again and remove the upper most heater hose from the heater core and raise the hose up high . Fill the rad until coolant comes out of the heater core pipe. Carefully reattach the heater hose. Fill the rad slowly allowing trapped air to escape.This may take a while. Once the rad is full put a catch basin on the floor under the rad filler neck.Start the car and let it run to operating temperature.Allow the expanding coolant fall into the basin.Once you see circulation in the rad you can slowly top the rad off.once you do this replace the rad cap and fill the reservoir bottle 3/4 ways to the top. Shut the car off and let it cool off filling the bottle as necessary.Hopefully this will cure your problem. Good luck :-)


Posted on Dec 13, 2008

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