Burping a radiator, question

Leave the cap off. Raise the idle to 1000 or higher. Get the coolant close to temp. Top off. Put cap back on. Drive. Recheck when it cools back down.

This time of year 160 should be good without releasing pressure when you take the cap off.

 

I posted Detroit’s instructions on burping the coolant system here (comment #12):

Engine Running and No Coolant Cap (Safe?)

 

I've always taken the top heater hose off when refilling a radiator from empty. Then all the air left in the engine is at the top of the head.

 

I know this goes agin all protocol, but what about taking a small propane torch and warm the thermostat housing? That'll open 'er up.

 

Take the cap off, plop down a 10 gallon or bigger container under the rad. Go get breakfast while she warms up.

Have gallons (Plural) of fresh fluid ready to add on as she approaches 180 or whatever you consider to be a working going down the road temperature. Since it is a function of how much pressure you can impose on the system it may not be very ... forthcoming with that hotwater.

At some point your big temperature check valves should open. Thats when you either puke out alot of fluid, add more until all the air bubbles have gone bye bye. I used to puke my old radiators all the time but it's been so long that I am not sure if you can get a computer truck to accept that the system has no pressure on it just yet because you left the cap off on purpose.

 

it is sucking in the hose. the cooling system is not 100% full, there is that air bubble i told you about several postings ago. had there been 100% coolant, this just would not happen.

do as i suggested, drive the steers up on some wooden boards, to raise the front end a few inches. the air trapped inside will stay there, since the truck is on "level" ground. you need to raise the front end to allow the air bubble to get up to the top and get out.

also, look for bleeder valves on the top of the engine, like at or near the thermostat. follow all the coolant lines for bleeder screws.

some idea on what and where they may be located.

 

Something just doesn't sound right. Like I say, in all my years, I don't ever remember having to bleed a system of air, unless something else is causing the air lock. Maybe a pin hole in a head gasket, forcing pressure into the system.

 

Bad radiator cap, will cause the hose to collapse like that.