Coolant flush procedure issue

[steve2]

flushing radiator for my 2013 M 7040. (1300 hrs) Block heats up almost overheating water and flush never released from radiator the hoses stayed cool while block just kept getting hotter. Turned off the motor drain block and radiator reinstalled 50% antifreeze. My first thought is before replacing thermostat buy a new radiator cap Thinking this is the least expensive option to start. please let me have some feedback about my approach. Should I just buy a new thermostat at the same time as the cap not sure how accessible thermostat is it’s crowded up in the front around the top of the radiator on this tractor.

 

[dusty3030]

When you say the block gets hot, how are you measuring the temp?
What does the temp gauge on the dash indicate?
It takes awhile to get a diesel that isn't under load to warm up and open up the thermostat. Infrared thermometer would be helpful for you to see what the temp actually is before you go to swapping parts.

Have you had some issues or are you just doing some preventative maintenance?

 

[steve2]

Thanks for quick response Dusty. —-preventive maintenance. The gauge was between the last and second from last lines below red “hot” lines and when working tractor thermostat releases typically between third and fourth lines below red hot line with gauge dropping to fourth line as normal operating temperature.

 

[dusty3030]

Sounds like you might have some air in there. You drained the old coolant already and are flushing with clean water and radiator flush if I'm reading correctly. When you drained it did you drain out the radiator and the block? There is a block drain just forward of the oil fill cap.

 

[steve2]

Sounds like you might have some air in there. You drained the old coolant already and are flushing with clean water and radiator flush if I'm reading correctly. When you drained it did you drain out the radiator and the block? There is a block drain just forward of the oil fill cap.

Uh

 

[steve2]

Yes drained radiator and block. Next Filled with water and drained radiator and block. next added flush and water filling until water came out top of radiator ran engine 2000 rpm fifteen minutes until temp gauge caused concern (see detail from original post) turned off waited a few minutes and as I was running out of time released pressure with 1/4 turn of cap which released fluid AND possibly air. Since Original post I called my local Kabota dealer. The new cap Is $54 new thermostat $66. Maybe before investing I should take it out run it to operating temperature watch what’s going on with the gauge? If thermostat releases all good. If not purchase new stat. Either way I’ll let it cool off open the cap and see if radiator is filled to top or if need to top off antifreeze. Overflow tank is filled already with new coolant mix. Thoughts?

 

[Chewwy]

It’s unlikey the radiator cap is your problem. If is is not leaking and the radiator and/or hoses have not blown due to overpressure, it is doing it’s job. You could remove the thermostat and see if that solves your block overheating issue, before buying a new one.

 

[RjCorazza]

Although I've never bothered, you can remove and test the thermostat in a pot of water and a thermometer. By the time it's removed you may as well just replace it.

 

[ruffdog]

Sounds like you might have some air in there.

I agree. Is there a vent in the system to bleed the air? Does it have a vented thermostat that prevents a pocket of air? I have drilled the 1/16" hole in many thermostats to prevent this. Many newer cars and motorcycles also have the bleed valve/screw. See article:

Air Venting

 

[RjCorazza]

I agree. Is there a vent in the system to bleed the air? Does it have a vented thermostat that prevents a pocket of air? I have drilled the 1/16" hole in many thermostats to prevent this. Many newer cars and motorcycles also have the bleed valve/screw. See article:

Air Venting

One of my wife's cars years ago had to be purged at the thermostat with a bleeder valve. Never seen one since though. Don't most thermostats have a small hole that allows coolant to trickle through when the thermostat is closed?