2002 Jeep Liberty coolant bleeding nut rusted shut

[Breesway713]

I need to bleed the air bubbles out of my cooling system after thermostat replacement. I cannot get the coolant bleeding nut off. It's rusted shut. I am at a loss. I've put lubricant and wd-40 in it already.

 

[david.lukac]

I was able to get mine out after soaking it with PB Blaster and gentle tightening/loosening. I put a bit antiseize on it afterwards. I’m not convinced tho it’s the best for place for bleeding the system- it sits well below the reservoir, so coolant comes out of it very early. I bled the system by idling on operating temperature for 5min with reservoir cap open - the level in reservoir is stable afterwards, but maybe I should still try to “burp” it. But I’m not too keen on opening it again - the bleeding nut is way too short for my liking and thread on it is not in the best shape.

 

[roger d]

I was able to get mine out after soaking it with PB Blaster and gentle tightening/loosening. I put a bit antiseize on it afterwards. I’m not convinced tho it’s the best for place for bleeding the system- it sits well below the reservoir, so coolant comes out of it very early. I bled the system by idling on operating temperature for 5min with reservoir cap open - the level in reservoir is stable afterwards, but maybe I should still try to “burp” it. But I’m not too keen on opening it again - the bleeding nut is way too short for my liking and thread on it is not in the best shape.

I bled mine a couple days ago. The coolant bleeder screw, OEM Part Numbr 6034331, was put on too tight. The torque is very low; 4 lbs I think. Anyway I soaked mine in PB blaster and tried loosening it with an 8 mm allen wrench. It did not come loose. I sprayed it again and let it soak a couple more hours. No luck. I sprayed it again and waited a couple hours. This time with the short side of the allen wrench on it I hit the allen wrench with a big wrench a few times and it turned. It was still tight but slowly came loose. I did not know it was short. I loosened and loosened to see coolant bleeding out but only had air so kept loosening it. Well I do not know where it went. The search started for a replacement. I stumbled into a Jeep forum and inside the article found the part number listed above. I found it on the internet including on ebay. The price was some high to more and the shipping was unreal. But I ordered one. It is still not arrived. After waiting a few days I decided to call local parts stores; no luck. I canlled a nearby Jeep dealership and got the help of an extremely helpful parts guy. I also discovered another part that works. It is made of brass, I thought that was good, and it is the same other than it used a 5/15 allen wrench. That part number is HHP12B. It is available on the internet for considerably less than the OEM part. I bought one from Oreilly Auto Parts, screwed it on some by hand, bled my system (after filling it up using the open bleeder port with the Jeep completely cold), and then finished screwing it down with an allen wrench and tightened it just a little (like an oil filter). Now I can go.