A couple of months back the top radiator hose blew out on my 4cyl 2.5L Dakota. This is the hose with the cap and housing in the center of the hose, between the radiator and the engine. My AC has been working fine, truck runs smooth after replacing the plugs and wires. But when I had to use the heater yesterday - no heat. The temp guage on the dash does not read hot even after a 20 minute drive to work on the freeway. So after a 10 minute drive this morning, the top hose is hot but the bottom one is luke warm. Same with the heater hoses - top one is warm, bottom one has no temp at all. The blower works fine in all positions.

Is there a proper way to burp the air from the system after replacing a radiator hose? The manual says that it regulates itself but there still has to be a way to get air out of the system after a blowout, right? Back in the old days, I took off the radiator cap and ran the truck with the heater on high. I tried this and coolant was burping out the cap (in the middle of the hose). Do I do the same thing?

And who had the great idea to house the radiator cap to the hose and not have the radiator cap on top of the radiator??? Seems dumb to me...
Thanks!

 

there is a sticky in the diy section about burping. but basically get the front end up higher then the rear end and let it warm up, make gravity do the work

 

did you replace the tstat. after i got a bad one i always boil mine before i put them in to check to see if they open.

 

I did not replace the thermostat. I guess for the price, it's a pretty cheap part of maintenance. That's a clever idea about raising the front end. I'll check out the sticky. Thanks, gertie240

 

You may have lost your water pump that could be why the hose burst also water boiled because the pump is not pumping water.

If that is the problem you need to fix it your temp is not correct its running very HOT not cold.

 

Only way to test for sure is remove the T stat completely put back together run with rad cap off look for the water flowing through the hose if no flow the pump is a goner.


Or your T stat is locked closed damaged

I almost forgot the rad filler and cap was moved to make them safer, or you could say so you dont try to open it unless the car is cool

 

Hey 98DAKAZ -
The temp gauge is readng normal, just below half. I'll try burping the system. I do recall seeing fluid running through the raidator looking in to in the filler opening. I'll check that again.

 

I have the front end elevated maybe 2" or 3" on the slope of the driveway. That's about the best I can do for now without putting a hydraulic underneath, and not really wanting to do that and chance ruining a jack.
I initially had the radiator cap off but it only took a miinute before the coolant began bubbling out and onto the belt below. SO i replaced the radiator cap but left the filler on top of the radiator open. The truck ran at idle for about 10 minutes before the fan kicked on (finally). Both upper and lower hoses are hot and there is some warmth to the air coming out of the heater vents. I cannot see for sure if the coolant is flowing through the radiator through the filler hole. I guess I'll let it idle for another 10 or 15 minutes.

 

Ok sounds like you are telling me two opposite things first you say the top hose is hot but bottom is not like it’s not flowing same with the heater hose. Now you are saying it is flowing fine and the temp is good?

Either your hose was old and burst or something is wrong it overheated and burst the hose?

I have never had to Burp my 2.5 even after dumping and flushing the system.


No argument just trying to get things straight

 

I can't SEE that it is flowing but both upper and lower hoses are hot. Maybe the thermostat just had to open?

I think the hose was old. I've had the truck for almost 5 years and never really looked at the hoses.

Maybe replacing the thermostat is the first, inexpensive option.