My Hoses have been replaced, thermostat is new and OEM temp rating. It normally sits around 190-200 (right below half to half on gauge). Today i noticed it was sitting at around the 260 right below the 3/4 mark on the gauge.

Now, i HAVE noticed that the upper and lower radiator hoses pinch after the jeep cools down. I'm not new to mechanics but have never had an issue like this with the hoses. I know the water pump is good cus its cycling the fluid through once the thermostat opens. Im pretty sure the fan clutch is good as well.

Also I have my electric fan hooked up as a constant running fan.

Any input would help! thanks a lot guys!

 

Rad cap is bad and 3/4 mark is 235 (mathematically).

 

Thanks after i posted this i threw the idea of a bad cap to the wife but figured id wait for some responses, and yeah 235 sounds more reasonable lol my mistake.

 

hoses pinch??????

 

yeah! lol its done it a lot. both hoses upper and lower pinch shut after it cools down. cap makes sense tho.

 

when you open cap do they expand back

 

yeah, also i noticed if i let it sit for a while they slowly expand back as well.

 

Rad cap has 2 valves and 3 sealing surfaces....all must function correctly.

 

Someone correct me if I'm wrong but shouldn't the lower hose have the spring inside it to keep it from collapsing? Not for this situation particularly but as a result of low pressure something or other?

 

ive been doing research on other forums and on here and find that most people say its the cap. im going to go get one now and put it on after it cools down and see how it goes from there. as for the hose, both upper and lower are new. however i dont think either of the hoses have the coil in them. they both came new from o'reillys without them.

 

You would think they did but no. Not all aftermarket hoses have the springs inside them.

 

With a properly functioning rad cap, the cooling system pressurizes to 15-16lbs at operating temp, why would a spring in a hose be necessary?

 

The lower radiator hose is under a "suction" A hose at high temps can softern and collapse. There must have been a reason they came that way from factory.

 

well i went and got a cap but the only cap they had for it was a 13lbs cap. not sure if i should use it or just return it tomorrow for one thats 16lbs. I just got home and was looking at the hoses while it was running. i revved the engine a few times and the top hose was fine but i did notice every time i revved the engine that the lower hose would slowly collapse more and more as the rpms got higher and higher. maybe i should just go and see if the auto store has one with a spring in it tomorrow?

 

Check your over flow/fill bottle, pull the fill line off it and make sure its clean, if all that is good its more than likely the Rad cap.