I am about to set this thing ablaze! I put everything back together, and the coolant does not seem to be circulating, it did this before but I figured the headgasket was so bad that it wouldn't let it build pressure, but it still does it. The two heater lines that run to the core get pretty warm, the bottom hose of the radiator gets a little warm, but the upper radiator hose seems to create a vacuum in it and sucks down on itself (like its pinching it off). The overflow bottle is filling up really slowly with green fluid, but the radiator is just full of water. I only idled it for a couple minutes because I don't want to overheat the head. Does anybody have a schematic on the cooling system or have any ideas? I am hoping to get this thing running today so I can head back to school!!! Feel free to give me a call on the cell, 763-238-9791.

 

Rad's blocked or t'stat is bad. Seems like your water pump is trying to circulate, unless motor heat is creating a pressure vacuum in the line and your water pump is actually NOT circulating...Sorry I can't be more specific. I've got a service manual, I'll take a look a little later but have to go out for a bit. Good luck.

 

Are you sure your belt is on right? It sounds like the characteristics of a backwards pump. You have the suction on the pressure side, the heat radiating from the suction side. The thermostat would keep it from circulating in that case. I tore my hair out on a Jeep with the serpentine pump in place of the v belt pump, they turn opposite directions.

The rotation being right, the thermostat is probably blocked causing a vacuum all the way to the top hose.

Also make sure the system is full, sometimes they don't fill the block right, pull a plug from the head and fill till it comes out the hole.

I almost cooked mine a while back because the block did not fill and the pump did not circulate. I always pull a plug now to make sure.

 

If the engine has only been run a few minutes, that wouldn't be enough time for the thermostat to open. If the thermostat is still closed, there would be almost no water movement in the radiator.

 

Ok take it from the elementry side. The system is stupidly simple. Water pump, thermostat and water. There is nothing else. Make sure the bypass is not plugged, very important, make sure it has water. It has to cool.... Not sure, pull a plug on the head and see if it shoots out. Pull a plug, start it, water should shoot out real good. If not look for a blockage. Like stuffing a rag in the hose to keep from junk getting in, not taking it out. How did I know that?

 

The belt was on right, I tried backflushing the radiator to get some crap out but nothing came out. I pulled the t stat just for fun and now its circulating just fine. I wanted to ask you guys before I started ripping the pump off. The tstat looked just fine except I had to mangle it to get it out. Apparently you can't find a thermostat for a Cummins at 6PM on Sunday night So the truck is parked till I get home on Friday. Does anybody have any preferences on a good coolant flush or solvent? I figure with all the crap I dumped in to get home I want to get it out of there. Sorry for filling up the help board with these issues...

 

You're probably fine to just pull the bottom rad hose and drain it and put in 50/50 antifreeze-water. Use distilled water from the grocery store or wherever, won't corrode. Any premium antifreeze is fine also. I just went through the same thing, except my hose didn't collapse. Similar symptoms though-had me all worried. Replaced my T'stat and all is fine.

 

ho2 pump gone S.?

 

No, the water pump is still alright, I could watch it circulate when I took the stat out. New one goes in tomorrow