Radiator & Air Bleed question
10-20-2007, 10:17 PM
#1
Radiator & Air Bleed question Ok, I've searched and come up with bits in different threads. So, here it is to summarize. My caprice had an LT1 before, now LQ9. I thought cooling system worked same way, so i put the air line that goes head to head into the fitting on the pressurized overflow, and after thermostat opens it spits coolant out of the overflow (i was running with the cap open to get rid of air).
now, from what I gathered from different threads, that air line cant go to a overflow. Some people T it into the upper hose, some T it into a heater line, some drill water pump and some drill the radiator tank. Are all of these ways accomplishing the same task equially well? Can I just tap into the upper radiator hose and froget about it? Should I switch to a radiator from a LS1 car? I am currently using an LT1 radiator that doesnt have a cap or a line for overflow. Side tanks are plastic, so i dont think i'll have much luck drilling it without leaks.
now, from what I gathered from different threads, that air line cant go to a overflow. Some people T it into the upper hose, some T it into a heater line, some drill water pump and some drill the radiator tank. Are all of these ways accomplishing the same task equially well? Can I just tap into the upper radiator hose and froget about it? Should I switch to a radiator from a LS1 car? I am currently using an LT1 radiator that doesnt have a cap or a line for overflow. Side tanks are plastic, so i dont think i'll have much luck drilling it without leaks.
10-20-2007, 10:50 PM
#2
All of those ways are trying to accomplish the same thing, to get any air pockets that develop out of the engine and to the radiator so that they can be purged from the system. While all of the ways will work IMHO I do think that some are better than others. The goal is to get the air pockets to the radiator cap so that as the coolant temp rises and pressure builds the air is forced out and then when it cools coolant is sucked back in from the overflow tank. So taking that into account
Running the line to the upper portion of the radiator tank is the best, T-ing it into the upper radiator hose is the second best, Tapping the water pump is the third best option, T-ing into a heater hose ranks 4th, and capping it would be the worst option. Some people have done fine by capping it and have no complaints, but I don`t think GM would have put the line there unless it was necessary. I have heard a few people say that as long as you purge the air out of the line when you fill the coolant you can cap it off........but I don`t think that is the best way of doing it. If the only reason for the line was to purge air when you fill the radiator GM would have just put a air bleed screw there instead of the bypass line.
Running the line to the upper portion of the radiator tank is the best, T-ing it into the upper radiator hose is the second best, Tapping the water pump is the third best option, T-ing into a heater hose ranks 4th, and capping it would be the worst option. Some people have done fine by capping it and have no complaints, but I don`t think GM would have put the line there unless it was necessary. I have heard a few people say that as long as you purge the air out of the line when you fill the coolant you can cap it off........but I don`t think that is the best way of doing it. If the only reason for the line was to purge air when you fill the radiator GM would have just put a air bleed screw there instead of the bypass line.
10-21-2007, 04:02 PM
#3
im going nuts! I have made a mess on my garage floor 3 times today.
I am using stock overflow which is T-ed into a heater house, and stock LT1 radiator with no cap and no provision for any tubes. First try, i connected the air tube that goes from head to head to the fitting on the stock overflow. Start the car, and I have one of those laser temp guns, so when the upper neck reaches 160 water starts coming out of the overflow.
then, I tried T-ing the air tube first in the upper hose, then in the lower hose, both with the same result.
I just dont know what im doing wrong, lower hose gets hot and upper one doesnt. I tried closing the cap, upper hose got hot, computer turned on the first cooling fan, then my upper hose blew apart, I used a piece of 1" pvc and hoseclamps to hold it together, i think i may not have tightened the clamp tight enough. Oh, and I've also changed the thermostat thinking that it maybe stuck, and waterpump is brand new. I cant figure out what im doing wrong, please help!
I am using stock overflow which is T-ed into a heater house, and stock LT1 radiator with no cap and no provision for any tubes. First try, i connected the air tube that goes from head to head to the fitting on the stock overflow. Start the car, and I have one of those laser temp guns, so when the upper neck reaches 160 water starts coming out of the overflow.
then, I tried T-ing the air tube first in the upper hose, then in the lower hose, both with the same result.
I just dont know what im doing wrong, lower hose gets hot and upper one doesnt. I tried closing the cap, upper hose got hot, computer turned on the first cooling fan, then my upper hose blew apart, I used a piece of 1" pvc and hoseclamps to hold it together, i think i may not have tightened the clamp tight enough. Oh, and I've also changed the thermostat thinking that it maybe stuck, and waterpump is brand new. I cant figure out what im doing wrong, please help!
