Cooling system

[Cheyenne1010]

I have a 1973 Chevy Cheyenne C10,been parked in the driveway since 2009(needed a transmission) it has a brand new water pump,thermostat,radiator hoses,radiator and coolant.So after sitting in the driveway for 9 years.I put a battery in it and it started right up.The problem I'm having is it spits out coolant out of the radiator,then I add what it spit out and then a few minutes later it spits out the same amount of coolant out again and the upper radiator hose is very hot to the point you can't even touch it.This happens after 15 minutes of it idling.The temperature senor is new and the gauge is reading normal not hot.I know how the cooling system acts when there's compression leaking into the cooling system when there's a blown head gasket and its really not acting that way or maybe I'm in denial. So any help or suggestions you guys might have I'd appreciate it thank you.


Robert

[Rapid Roy]

Welcome

[Cheyenne1010]

Thank you,cool web site.I got a 1973 chevy cheyenne10 long bed,350 motor with automatic 350 turbo

[blazer74]

Is this with the cap off and just sitting?

[Cheyenne1010]

After I let it idle for about 20 mins and then I turn it off the upper radiator hose is rubbling like its boiling.when I touch the hose its very hot.temp gauge reads normal.

[Rapid Roy]

Can you post a pic of your fan area with possible radiator also? Could be various things. Radiator, fan, clutch, shroud, etc.

[Henry]

Hi Cheyenne:
So when you say the cooling system components are all new, did you just install them recently?...or did you install them 9 years ago and they have just been sitting unused on the engine?

When it is warmed up do you feel a temperature gradient across the top of the radiator?...it should be real hot on the drivers side and then get cooler as you get to the passenger side. Return hose to the engine should be much cooler than the supply hose.

Are you sure you installed the thermostat right side up?

Regards,
Henry

[Cheyenne1010]

I installed all the cooling components for the cooling system about a week ago and the thermostat was installed correctly. Is there a chance that the head gasket might have a leak close to one of the Pistons and water jacket?

[blazer74]

Spitting out coolant?

With or without the cap on?

Pressure changes the boiling point.

Overcoming the rad cap while running and overflowing is a sign of a bad or incorrect cap. Also over heating causing too much pressure.
Last a bad head gasket or worse.

You can rent a pressure tester for the cooling system that replaces the cap, pump up the pressure in the rad and see if it holds pressure or not.
If no you have a leak somewhere.

With the cap off and fully warm and the thermostat opens can you see water flowing in the radiator?

If you have no flow the thermostat is not opening, the water pump impeller is rotted away or a blockage somewhere.

[Cheyenne1010]

Waterpump is new,everything that has to do with the cooling system is new.after about 20-25 mins of running i take the radiator cap off to check the coolant level and before I can add more coolant it starts to come out of the radiator.it doesn't shoot out of the radiator like an over heated car,it comes out like your pouring it out of a coolant container.the fan is bolted on right and it does have a fan shroud.i heard that a bad fan clutch might not be sucking enough air through the radiator.

[FlatBlack77]

So you are letting it warm up for over 20 minutes with the cap on. Then taking the cap off and coolant is coming out because it is hot and has built up pressure in the system.

[blazer74]

Waterpump is new,everything that has to do with the cooling system is new.after about 20-25 mins of running i take the radiator cap off to check the coolant level and before I can add more coolant it starts to come out of the radiator.it doesn't shoot out of the radiator like an over heated car,it comes out like your pouring it out of a coolant container.the fan is bolted on right and it does have a fan shroud.i heard that a bad fan clutch might not be sucking enough air through the radiator.

That’s what we needed to know, cap off.

Like said above, heat expansion and pressure.

Removing an installed cap on a hot engine can be dangerous.

[Cheyenne1010]

Thanks guys for the info