dead issue but i still need help

[comancheman]

closed coolant system 4.0

flushed heater core

flushed block by running a garden hose into the small hose on thermostat housing and then out of the hose by the thermostat that runs to the heater core then pulled off lower hose and drained the radiator.

 

replaced radiator and hoses attached lower hose and filled radiator through upper hose. i tried to fill the block through the tube that runs from the block to the heater core but couldnt fit much at all.

then i filled the pressure bottle half way with coolant. i have about 4 or 5 gallons of old anti freeze that i drained but could only fit three gallons of new anti freeze. i ran the truck till the uppper hose was hot and then for a few minutes after that. The coolant level in the bottle would go up when i loosend the cap. and it would bubble when i revved the truck but the level never went down so i could add more.

 

any suggestions?

[JeepcoMJ]

run it with the cap off so the air bubbles out. it has no way to escape.

 

there's a trick to filling a 4.0...I can't remember if you're supposed put the truck facing downhill or uphill....uphill I think. that way the bubbles get out.

 

someone correct me if I'm wrong.

 

 

closed systems are a b*tch. you'd be best off removing the closed system and getting a full-core heavy duty radiator with a filler neck built into it...and eliminate the closed system.

[Pete M]

Park the truck downhill (or raise up the rear on stands) and bleed the air out the temp sensor located at the back/top of the engine.

[JeepcoMJ]

[comancheman]

so put the rear on stands and run the truck with the temp sensor removed?

[Pete M]

Be very careful though. Start with the engine cold (rather than hot), use a towel to cover the sensor hole, and have someone ready to kill the engine. And don't forget to wear eye protection! Antifreeze can come squirting out when you least expect it.

[comancheman]

so, lift up rear end, remove temp sensor, start cold motor and run it until coolant squirts out hole.

pressure bottle cap on or off?

[JeepcoMJ]

it'll be off. you'll be filling the reservoir as you go. keep it at least half full so that you don't suck any more air into the system.

 

remember, the goal is to get the air out...and that means no more coming in.

[Eagle]

Fill the bottle half way. Run the engine with the cap off until the coolant in the bottle starts to bubble. Shut off the engine and stand by. As soon as the bubbling stops, the coolant will start to suck back into the system. Pour more into the bottle, to keep the level about half full. Once it stops sucking in coolant, start the engine and repeat. It'll probably take three to four cycles to fully "burp" the system.

 

Wear heavy rubber gloves and safety glasses when pouring in the coolant -- anything that splashes out WILL be boiling hot (+/- 240 degrees).

 

I don't remove the temp sensor. It's lower than the bottle, so burping air from the head doesn't really purge the system.