Lower radiator hose cool/Water pump squeal

99 Blazer, 4.3, 4wd

I just finished replacing the head gaskets/passenger head last week and found a leak in the radiator today so had to replace that as well. I am wondering if it is normal with a new rad and having a "clean" system that the lower hose stays cool? All the other hoses are hot, am getting heat, running normal temps and no other cooling issues noticed. Also at startup I am getting a squeal seemingly from the water pump (replaced this January) that goes away most of the time after it warms up. Any suggestions?

99 Blazer, 4.3, 4wd

I just finished replacing the head gaskets/passenger head last week and found a leak in the radiator today so had to replace that as well. I am wondering if it is normal with a new rad and having a "clean" system that the lower hose stays cool? All the other hoses are hot, am getting heat, running normal temps and no other cooling issues noticed. Also at startup I am getting a squeal seemingly from the water pump (replaced this January) that goes away most of the time after it warms up. Any suggestions?

Is heater working good?
Any coolant leaks.
Is the running tempt holding around 195 degrees?
It is normal for lower rad to be cooler.
Hot coolant comes into rad from top hose and cools as it goes threw rad and should be cooler coming out at lower hose.

ON water pump noise make sure pump is not lose or leaking.

Then check belt and belt tensioner and also alternator bearings.

Heater working good, no leaks, running 195ish and holding steady. I put a sound mic around all the pulleys/pumps/alt/belt and around the water pump housing and the noise seems to generate at the water pump. I will have to check to make sure the pump is not loose and belt is ok. Thanks MT for your input...

Heater working good, no leaks, running 195ish and holding steady. I put a sound mic around all the pulleys/pumps/alt/belt and around the water pump housing and the noise seems to generate at the water pump. I will have to check to make sure the pump is not loose and belt is ok. Thanks MT for your input...


You are welcome and let us know how it goes.
Make sure belt is not dry to.
Drop a little water on belt with engine running and see if noise changes.
Was that a rebuilt water pimp or a brand new one?
Good Luck

What you are probably hearing is the belt Squealing. I have to replace mine every 2 years or it squeals until it gets warm. If you haven't replaced your belt recently, take a look to see if it is cracked etc. if it has been awhile since you replaced it, I'd try putting on a new belt before trying to replace all of the other components.

Try the water thing on the belt and if the noise stops, replace the belt.

Tried the water trick and sure enough it stopped for a quick second and then started back up, so I replaced the belt w/ a Goodyear Gatorback and it is quiet as can be. Thanks again for all the contributors on this site, it sure helps keep one sane.

Tried the water trick and sure enough it stopped for a quick second and then started back up, so I replaced the belt w/ a Goodyear Gatorback and it is quiet as can be. Thanks again for all the contributors on this site, it sure helps keep one sane.

You are welcome and thanks for posting back how it went and the fix.
Good Luck

:cheers: Congrats man :bananasmi