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Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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| | | | Joined: Jun 2015 Posts: 8 New Guy | | New Guy Joined: Jun 2015 Posts: 8 | after getting my gmc running it started overheating severely and started pouring steam out of the radiator, what could be causing this ive checked my water pump and it seems to be alright and there seems to be no blockage in either the engine or the radiator | | | | | Joined: Mar 2000 Posts: 1,177 Red dot, center of chest ... | | Red dot, center of chest ... Joined: Mar 2000 Posts: 1,177 | If you are certain that there's no obstruction in the block or head and the thermostat is opening correctly, then it's probably a blown head gasket. | | | | | Joined: Jan 2008 Posts: 4,961 'Bolter | | 'Bolter Joined: Jan 2008 Posts: 4,961 | Did you just now get it running? It sounds like you didn't purge all the air out of the head when you filled coolant. | | | | | Joined: Jun 2015 Posts: 8 New Guy | | New Guy Joined: Jun 2015 Posts: 8 | what would be the correct procedure for purging the air from the head?,this may be the problem | | | | | Joined: Jun 2011 Posts: 5,096 Crusing in the Passing Lane | | Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | Like Paul said, make sure the thermostat is opening-put the unit in a pan of water on the stove and observe. 190 or 195 degrees F would be good.
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
| | | | | Joined: Jan 2008 Posts: 4,961 'Bolter | | 'Bolter Joined: Jan 2008 Posts: 4,961 | First of all, the thermostat should have a small vent hole in it for air to escape. In addition to that, I usually apply about 5 lbs of air pressure to the cooling system. I then crack the temp sender and make sure coolant comes out. Loosening heater hoses to purge the air helps too. Steam does not mean hot water. It means no water somewhere. | | | | | Joined: Jul 2014 Posts: 48 Wrench Fetcher | | Wrench Fetcher Joined: Jul 2014 Posts: 48 | Retarded timing, vacuum leaks, and lean fuel mixture all cause overheating as well. Try 10-14 degrees BTDC at idle for a base timing setting. | | | | | Joined: Jun 2015 Posts: 8 New Guy | | New Guy Joined: Jun 2015 Posts: 8 | thank you for the help , filled it up and bled the air and it ran amazingly cool. | | |
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