ktmrider
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I installed a new radiator about a month ago and I used the heat yesterday and at idle the heat goes away. Think I may have not have bleed the system completely. Any tips on getting all the air out of the cooling system?
Bleeding 3.7 cooling system
- Thread starter ktmrider
- Start date
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dude1116
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Run the heat, open the Rad cap. That's about all I had to do. Add coolant mix to replace the air.
tombo_ontario
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theres also a bleed screw on the upper coolant hose but i've done what dude1116 said several times and never had a trapped air issue.
uss2defiant
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unless you installed the thermostat incorrectly.
ktmrider
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Was really hot then I put the radiator in. I'm pretty sure I forgot to run the heater when I was adding coolant.
I currently have the same exact issue and have had no success with bleeding or burping the system. Not sure what I am doing wrong? The temp gauge is always at just a needle below half so I don't have any themostat or overheating issues. Do you get get a sloshing sound in the heater core behind dash as well?
Hockeygoon
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What does running the heater do? On most systems the coolant is constantly running through the heater core no matter what the blend door and fan are set to - is the Liberty different?
tjkj2002
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Just tells you that you do not have a air pocket trapped in the heater core in a KJ,most common place for it to get trapped.
dude1116
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It's opening the rad cap that lets the air out of the system. 
Otherwise the system stays pressurized and the coolant level will never drop to replace the air in the system with coolant.
Otherwise the system stays pressurized and the coolant level will never drop to replace the air in the system with coolant.
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tjkj2002
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That's actually false.It's opening the rad cap that lets the air out of the system.
dude1116
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So if it's false go ahead and explain it. I like to know WHY I'm wrong. Not just that I'm wrong.
tjkj2002
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Pressure or no pressure at some point the trapped air pocket will make it's way to the highest point.Those tricky cooling systems(anything with the 4slow in it,and most GM's) I use the no-spill funnel and run(no pressure) till boilover,plug funnel and turn off engine(builds pressure),wait 2-3 mins(cools and creates vacuum) and pull plug out and coolant get's sucked in to fill the trapped air pocket.
Some Ford's have a specific bleed instructions,fill system,put pressure cap on and run at 3000rpm's for 10mins,shut off engine and top off as necessary.
PunkChachi
Full Access Member
Would I be able to accomplish the same thing by taking a hose and routing it from the bleeder point to the opening in the overflow tank and submerging the hose in the overflow tank. Then instead of "plugging the funnel" at boil over, just pinch of the hose?
To me, this aspect of the Liberty is the worst part I have encountered so far with my 2007. I think my biggest issue leading up to this was I could not get my bleed screw out of the upper goose neck. Every time besides the last time I would have to back it off a bank to finish filling and bleeding it, which was a whole process.
This last time though I was able to get that bleed screw out no problem. I don't know if it was factory or 1st service... but mine had red loctite is why I couldn't get it loose. And I probably worked that stuff loose over time and by nearly overheating trying to bleed air out.
For me the trick after a flush is now I just put a small funnel in that bleeder and I start by filling the engine from there. This seems to push the air right out. Then I fill up the radiator, fire it up, make sure it is all good to go. It was also helpful that last time I caught and measured every bit that came out of the system. So I knew what had to go back in, and I had very little trouble getting it done this time around.
This last time though I was able to get that bleed screw out no problem. I don't know if it was factory or 1st service... but mine had red loctite is why I couldn't get it loose. And I probably worked that stuff loose over time and by nearly overheating trying to bleed air out.
For me the trick after a flush is now I just put a small funnel in that bleeder and I start by filling the engine from there. This seems to push the air right out. Then I fill up the radiator, fire it up, make sure it is all good to go. It was also helpful that last time I caught and measured every bit that came out of the system. So I knew what had to go back in, and I had very little trouble getting it done this time around.
I've ran it with just the rad cap off and it worked fine. Last time I filled the reservoir to the line, then filled it full through the bleed screw, put the bleed screw back in and ran it for about 10 mins, (with the cap off) the level in the reservoir dropped a few times and I topped it off, had heat quickly. Done. Checked it for a few days following and it stayed at a constant level.
Damotee
Full Access Member
An effective method I use is once you have replaced the fluid, start the engine and loosen the bleeder valve so that a small amount of coolant and air bubbles start bubbling out. Keep doing this until no more air bubbles come out.
Is the reservoir cap on or off with bleeder valve loosened?
