1981 F150 Radiator Problem?
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1981 F150 Radiator Problem?
I have a 1981 F150 4x4 with 302 and NP435 that I recently bought for $250. But when I run it for over 5 min its starts to overheat. I also noticed that the top radiator hose bulges.
So I decided to see if it was the thermostat but that didnt help either so I bought another thermostat but it still didnt help. So I decided to run it without a thermostat but then it still did the same thing it overheated and the top radiator hose started bulging.
Could the radiator be plugged or what would cause this to happen?
So I decided to see if it was the thermostat but that didnt help either so I bought another thermostat but it still didnt help. So I decided to run it without a thermostat but then it still did the same thing it overheated and the top radiator hose started bulging.
Could the radiator be plugged or what would cause this to happen?
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From: Bama Gal transplanted to the Pacific North West
1981 F150 Radiator Problem?
check your water pump?
also ya should flush your cooling system...see if your radiator even drains....mine was so full of crud that it would just let a trickle out when i opened the drain plug...even if you go with a new radiator, flush your cooling system completely so you don't fill your new one with all the junk that's in the heater//engine..
there's several companies who make a kit which attaches to one of the heater hoses, and to your garden hose...the chemical flushes are great for getting rid of depostis etc...but a complete flush with the hose kit...gets into every nook and cranny of the cooling system...btw read the directions first
also ya should flush your cooling system...see if your radiator even drains....mine was so full of crud that it would just let a trickle out when i opened the drain plug...even if you go with a new radiator, flush your cooling system completely so you don't fill your new one with all the junk that's in the heater//engine..
there's several companies who make a kit which attaches to one of the heater hoses, and to your garden hose...the chemical flushes are great for getting rid of depostis etc...but a complete flush with the hose kit...gets into every nook and cranny of the cooling system...btw read the directions first
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From: Rose City, MI
1981 F150 Radiator Problem?
if it was my truck i would go ahead and change the upper and lower radiator hoses and see if that helps to. The bulgeing upper hose makes me think that its gotten soft over time and is going to blow out on you soon. So replace the upper hose for sure and check the rest for soft spots. then check your water pump. Also make sure your lower hose isn't colapsing from the pressure of the water pump sucking the fluid through it.
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1981 F150 Radiator Problem?
Just from recent experience if you are gonna replace that radiator find you a salvage yard with a 'guru' in it. I'm mechanically inclined enough to fix things when they break if I have a haynes in front of me but I don't have 'mechanics' knowledge of cars and stuff.
I had a hell of a time finding a used radiator for my 1983 F150 with a 351w until I found a good 'guru' who was willing to dig thru his brain and figure out that a later model Lincon's radiator would work just as well even though it was an inch and a half shorter than mine. just took some 'extra' mounting thinks (nylon ties and mechanics wire) to put it in place and saved me about $90 on buying a remanufactured radiator.
I had a hell of a time finding a used radiator for my 1983 F150 with a 351w until I found a good 'guru' who was willing to dig thru his brain and figure out that a later model Lincon's radiator would work just as well even though it was an inch and a half shorter than mine. just took some 'extra' mounting thinks (nylon ties and mechanics wire) to put it in place and saved me about $90 on buying a remanufactured radiator.
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1981 F150 Radiator Problem?
yah i bought another radiator from a junkyard for $35. Ill change the hoses while im at it to i think
thanx
thanx
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From: Rose City, MI
1981 F150 Radiator Problem?
yes definitly change the hoses while you are at it. They arent really expensive and will save you lots of pain and anguish. and since you will be draining the radiator anyway go ahead and replace all of them even the ones to the heater. When i got mine i had a slow leak i had to put about a quart or so a week in it. It wasnt burning it or anything just was always low. i put new upper and lower hoses on and no more leak and it runs cooler too. 
Good luck with it. Oh another thought......... try running it with the heater on high after that if it still gets hot to see if that helps to cool it some. Also make sure you have all the shrouds in place. I have a single core radiator on mine and i desperatly need a 3 or 4 core. I sit at a stop light and i can watch the gauge go up, start moveing again and it cools back down. I guess thats what i get for transplanting a michigan truck to oklahoma.
Good luck with it. Oh another thought......... try running it with the heater on high after that if it still gets hot to see if that helps to cool it some. Also make sure you have all the shrouds in place. I have a single core radiator on mine and i desperatly need a 3 or 4 core. I sit at a stop light and i can watch the gauge go up, start moveing again and it cools back down. I guess thats what i get for transplanting a michigan truck to oklahoma.
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