Champion Radiator Install Question

BBslider001

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Son of a *****. Should have left well enough alone. Changed the oil, all good. Change the T-Stat to an AC Delco 195 and the damn thing overheats on the test drive. Didn't hear the fan clutch kicking in....a 2 month old HD Hayden. I spin it and it's dead. It will not engage. So I am going to change the clutch and T-Stat this evening.....AGAIN. Should have just left it alone. I have no idea why a pretty new fan clutch takes a dump. The 180* is going back in, end of story. I HATE doing the same job twice.
 
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L31MaxExpress

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Son of a *****. Should have left well enough alone. Changed the oil, all good. Change the T-Stat to an AC Delco 195 and the damn thing overheats on the test drive. Didn't hear the fan clutch kicking in....a 2 month old HD Hayden. I spin it and it's dead. It will not engage. I can hold it while the engine spins LOL. So I am going to change the clutch and T-Stat this evening.....AGAIN. Should have just left it alone. I have no idea why a pretty new fan clutch takes a dump. The 180* is going back in, end of story. I HATE doing the same job twice.
Fan clutch has to have heat to engage. If the thermostat is hung closed it will never engage because the radiator is still cold. Thermostat might be stuck closed because of an air pocket in the system. I have drilled a small hole in my thermostats for years to prevent an air lock. I drill a 1/8" hole, it does not noticeably slow down the engine warm up and allows the engine to run at a more stable operating temp. The hole does 3 things. 1st it vents air and steam to the radiator. 2nd it helps keep the heads cool by allowing more water circulation before the thermostat opens. 3rd it prevents the thermostat from completely blocking off the radiator, allowing ice cold water to surge into your hot block and thermo stress it. Thermo stress leads to cracked parts over time.
 
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BBslider001

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Fan clutch has to have heat to engage. If the thermostat is hung closed it will never engage because the radiator is still cold. Thermostat might be stuck closed because of an air pocket in the system. I have drilled a small hole in my thermostats for years to prevent an air lock. I drill a 1/8" hole, it does not noticeably slow down the engine warm up and allows the engine to run at a more stable operating temp. The hole does 3 things. 1st it vents air and steam to the radiator. 2nd it helps keep the heads cool by allowing more water circulation before the thermostat opens. 3rd it prevents the thermostat from completely blocking off the radiator, allowing ice cold water to surge into your hot block and thermo stress it. Thermo stress leads to cracked parts over time.
It opened and cooled off a few cycles, then just got hot, so there is heat there. The hole is a great idea though and I will do it. The fan clutch has been working great. Odd that it just quit. I guess I am wondering if I should replace? It's cheap enough.
 

BBslider001

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Get a thorough bleed on the cooling system before you go tossing that fan. Yes, our trucks are reverse rotation.
What is the best way? Are we talking another full flush or just burping with he cap off? Very much appreciated.
 

BBslider001

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Raise the front end of the truck and burp with the cap off. I highly recommend the Lisle coolant funnel. I use it on everything, and makes bleeding the coolant easy.
www.amazon.com/Lisle-24680-Spill-Free-Funnel/dp/B00A6AS6LY
I'll get it ordered. Thanks! I will say with 100% certainty that I have no fan clutch. Added about a half gallon of coolant last night, burped it, drove it, and it gradually climbed to the 240 range with zero fan noise or engaging. Ordered a new GM clutch last night. I'll report back. Odd that an HD Hayden crapped out after two months.
 

BBslider001

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Ok, update....and this gets interesting. I thought my issue was the fan clutch because it was not engaging like it should at 210*. I put a new one on last night, went for a drive, and the same issue happened....slow climb 235* before I got it home and no fan enagegment. Lemme back up to before I did that. I opened the rad cap before I started working on it and there was quite a bit of pressure and the top hose was pretty hard. Hmmmm, pressure? After cooling all night? That was my first indicator. Went for the test drive after the clutch change and same issue....getting hot and won't cool off. I pop the hood when I get to the house, and it is HOT on the engine side. I mean, it's hot here in Texas, but you could tell the engine was not getting cooled off at all. The top hose is hard as a rock and the fan clutch is not engaged like it should be. Call me crazy, but here is my theory. The ONLY thing I changed before all of this was the T-stat. I believe that is the culprit in this equation. It is not opening like it should and the water in the rad is staying fairly "cool" enough as to not get the clutch hot enough to fully engage. Since the t-stat is not opening, water doesn't circulate into a hot engine. This causes pressure (or back pressure) so the hose gets pressurized, radiator is too cool for the fan, and the engine overheats. Make sense? No coolant circulation would cause all of this. I am going to go back to the 180* since I have it to see if it will even keep it from overheating, not becaue I think a cooler t-stat will keep it cool, but because hopefully it will simply work at all. I don't think the AC Delco is opening. I had this same issue on my '94 I had years ago. I put a new t-stat in when I flushed coolant. First test drive, overheated and system pressuirzed. Pulled t-stat and drove it home....no issue. Ah! Put old T-stat back in and it was fine. Hopefully that is the deal this time as well. I will report back.
 

Erik the Awful

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Above 20 mph or so the fan has little to no effect. You can drive down the road with no fan so long as you keep moving.

The top hose is hard as a rock
That sounds like a blown head gasket or a cracked head or block. When running with the radiator cap off, does the coolant bubble constantly?
 
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