collapsed upper radiator hose

[coxfmly]

Hello,
I replaced my thermostats with GM factory units and now its running hot.
I installed the thermostat with the small weep holes in the rear position. The taller unit was forward. pointed ends up with the springs lowered into the housing. Used a previously posted diagram for guidance.

Removed and replaced 3 gallons of Dexcool and filled until fluid came out of seep hole.
After driving around last night it never cooled to 180 reading.
Upper hose didn't pressurize as i would have expected.

Checked this morning and the upper radiator hose has completely collapsed.
Pulled cap and the pressure was released.

I have just read about warming it up and revving past 3k a few times.
Will try that today. Assuming I have air in the system?

Thanks

[DmaxMaverick]

Sounds like typical air in the system after a service (R/R of coolant). Loosen the cap at least 1/2 turn, warm it up to about operating temp, and run several 20-30 second cycles of WOT (hold the pedal to the floor, it won't hurt anything), followed by a minute or two at idle. Watch the coolant level between cycles, as it should decrease as air is being replaced with coolant. The level should decrease after several seconds to a minute or two after returning to idle. Continue until the coolant level in the tank no longer moves. It may take as many as 2-3 cycles to see any movement, and it wouldn't be uncommon to take 8-10+ cycles to complete (typical is 4-5, the book says 3+). If the coolant level in the tank goes below the hose, you'll have to start all over again. It's better to keep it overfull (above the full line) and pull some out when you're done, than run it empty. It may take a little more coolant over time and a few hundred to thousand miles.

[coxfmly]

Perfect, let go and and give it a whirl.

[coxfmly]

Well, I tried for over an hour to get the air out...no go.
the temp wouldn't regulate down to 180 area.
I tightened the cap and the system wouldn't pressurize?
Upper hose stays very soft....could it be the radiator cap?

When its sealed up and I squeeze the hose I can hear the water "swishing" and then the fluid in the tank moves. I know the connection but it just sounds like a major amount of air.

i measured the fluid removed and i replaced it almost the the oz. going back in.
I don't believe I'm that far off with the refill.

Even with the temp being higher the fan clutch never "kicks" in.
fan turns but it doesn't lock up.

hmm....

[rapidoxidationman]

If I remember correctly, there is an air bleeder port on top of the thermostat housing. Putting the front of the truck higher than the back, however you can do that whether it is with ramps, a bank, just a hill, or whatever, will also help to get the air to where you can bleed it out at the thermostat. I don't think you're going to get much air out of the overflow tank, because the elevations of the plumbing involved won't let it happen.

[Kennedy]

If I remember correctly, there is an air bleeder port on top of the thermostat housing. Putting the front of the truck higher than the back, however you can do that whether it is with ramps, a bank, just a hill, or whatever, will also help to get the air to where you can bleed it out at the thermostat. I don't think you're going to get much air out of the overflow tank, because the elevations of the plumbing involved won't let it happen.

Yep

Open air bleed until liquid comes out. If it does not then add coolant until the level is high enough. Don't be afraid to fill to the protrusion at about an inch above the mid seam. Once liquid comes out start and run the engine and it should bleed just fine. Top off the surge tank as necessary.

[coxfmly]

Hello,

I was having a bit of trouble with the purge tank optics.
From the side it looked as if it was filled to the proper level but when I looked into the fill port it was at the top of the tank. It was quite odd to see it surge out of the top when from the side it was half full..

Well, It has finally purged itself and is running within specs.
Funny thing is, I drained 3 gallon, refilled with 3 gallons and in the end it required another gallon to top off. Maybe it had air in the system all along.

Thanks for all your help, Paul

[rapidoxidationman]

All told, the cooling system capacity is about 24 quarts.

[Kennedy]

Hello,

I was having a bit of trouble with the purge tank optics.
From the side it looked as if it was filled to the proper level but when I looked into the fill port it was at the top of the tank. It was quite odd to see it surge out of the top when from the side it was half full..

Well, It has finally purged itself and is running within specs.
Funny thing is, I drained 3 gallon, refilled with 3 gallons and in the end it required another gallon to top off. Maybe it had air in the system all along.

Thanks for all your help, Paul


The way that the tank is baffled it tends to allow some reserve space for expansion preventing complete fill errors. Often we fill to near the rim as it settles out to right about full once run and completely purged.

[More Power]

The spring side of the thermostat(s) should point toward the hot side of the cooling system (the engine). If you're concerned about whether the new t-stats are opening at the correct temperature, remove them from the engine and place them in a pan of water, raise the temperature, and using a cooking thermometer, see when the flow valves in each t-stat begin to open.

Back in 2016 when I had my truck's water pump replaced, the tech didn't open the air bleed valve on the t-stat housing. I asked him why. He said it wasn't necessary.... Turns out he was right. He filled the surge tank to the cold fill level, started and drove the truck around the block, then topped off the surge tank when he drove it back into the service bay. I was surprised, but it worked...