Air in Cooling System

[Kizer]

I can fill & bleed my cooling system ..everything works great UNTIL... at some random moment/temp the coolant starts to blow out of the reservoir. It finally reaches a level where the radiator is about a gallon short of full..then runs hot...about 220.
Any thoughts gentlemen?
Thank you.

 

[franklin2]

How full is the reservoir when you start this cycle? Does the tube in the reservoir go all the way to the bottom?

 

[Kizer]

I start @ "full when hot" knowing that's a little too much.
Tube goes to the bottom. .never draws the reservoir empty.

 

[riotwarrior]

Look at a vacuum fill and see if that helps?

 

[Kizer]

Sorry.? How do I vacuum fill?

 

[LARRY RANALLO]

Could be a blowen head gasket ?

 

[icanfixall]

Remove the small line from the radiator neck to the overflow tank. Make sure it will pass air but. Remember the radiator pressure will push out up to 16 lbs depending on the lbs radiator cap you have. Many times the line is partly plugged and wont suck back enough to refill the radiator as designed.

 

[Kizer]

Thank you ICANFIXALL.
It's definitely drawing off of the reservoir. .the overflow tube is passing air.
There's 20* difference between radiator in/out.
Is that normal?

 

[riotwarrior]

Look here this tool allows a vacuum fill of cooling system...draw vacuum, then turn off, wait if drops vacuum you have a leak if not, switch to a clean container full of coolant and it sucks it in filling all the voids

http://www.oilburners.net/forums/showthread.php?69668-Cooling-system-Vacuum-fill-tool

Maybe harbour freight or ebay for tool...

 

[typ4]

These trucks are stupid simple to fill the cooling system. Check fan operation and also on a dead cold start let in run for 30 seconds then pull the cap, if it has a bunch of pressure you have issues, head gasket or head crack.

 

[Kizer]

Thank you gentlemen, for the tool link and advice. Will check system pressure @ cold start ASAP.

What is the process for checking fan clutch performance, please?

 

[Kizer]

There's no early pressure build up in the radiator.

 

[Kizer]

What should water temperature difference be between:
thermostat housing and top of radiator?
top & bottom of radiator?
I get 209 at t'star, 178 at top of radiator and 186 at radiator bottom.
Seem right to y'all?
Can anyone school me on proper fan clutch test?
Thank you for your help/input.
Kizer

 

[eastsideauto]

I am having similar issues. Truck is running way on the upper end of the "factory" gauge. I know I need a real gauge but haven't had time to yet. My overtemp light has NEVER came on. When I cut the truck off after my evening ride home from work there is a lot of pressure in the radiator. The upper radiator hose is rock hard. Ran the chem test to check for exhaust gases in the coolant...negative. Did the cold start crank then run for 30 seconds...no pressure. Is there a way to see if the overtemp light actually works? I have a reall coolant temp gauge on my to-do list.

 

[icanfixall]

To test the overtemp sender thats in the front of the drivers side head remove the wire and ground the wire. Do this warm or cold engine. If the dash gauge swings well past the "L" then the sender is working. All the sender does is pegs the gauge when the coolant temp reaches 242 degrees.