DK35 Coolant issue

[Roscoe294]

Update...I put the radiator pressure tester on the radiator and started the engine. Within 20 seconds pressure climbed to 20+ psi and was still climbing until I killed the motor.

 

[jabelding]

Sounds like you need a head gasket. It is fairly involved to do it correctly I would take it to a dealer or a trusted independent that knows kubota or Kioti engines they are almost the same.

 

[Coyote machine]

Sounds like gasses of combustion are passing from the cylinder(s) past your head gasket into the coolant system, causing the rapid rise in pressure shown on the radiator pressure testing gauge.
Once you have removed the head and it's gasket, make sure the gasket is the failure point, and not the head itself from a crack or warp, etc.

 

[adventure bob]

Sad to say that it does indeed sound like a head gasket leak. Not sure of your tractor, but most combustion engines run about 15PSI. Check your radiator cap though because some run as high as 30PSI. Your cap relief pressure gives you the high end of where you should be because your cap should vent at that pressure.

 

[ritcheyvs]

Looking at the MIE online parts catalog, you may have one of two different engines. Engines up to s/n E614-00284 had the external stop solenoid on the right side of the engine (as an easy way to ID that engine). From s/n E614-00685 on, the stop solenoid is bolted to the front of the engine block. These two versions use a different head gasket AND there are at least two versions of the newer version head gasket and four versions of the older style, where newer versions superseded older versions.

It looks like improved versions of the head gasket were developed during production. Discuss this with your dealer/mechanic to endure you get the best replacement gasket. Also, be sure tour dealer/mechanic checks the head and block for flatness before reassembly and checks/replaces the head bolts as required.

I have a 2006 DK45s with the newer (front stop solenoid) engine however the only service manual for the DK45s only addresses only the older type engine. I believe the newer engine is the same as a DK40se, but that's a guess. So it may take some communication with Kioti to determine the correct head bolt specs and torquing procedures, which tend to depend on gasket type. Head bolt replacement (if so specified) and proper torquing tend to be critical in head gasket longevity.

 

[Roscoe294]

I graded the driveway tonight and noticed after I lost my top off coolant my temp gauge was all over the place.
At one point it was showing near overheat. I felt the radiator cap along with both top and bottom hoses. They were cool to the point where I could hold onto them.
Shortly there after the temp showed operating range and they were hot to the touch.
Could this simply be a fault t-stat? Although that doesn't explain the building pressure.
I'm just trying to start at the easiest, simplest thing first before I haul it off to the Desiel mechanic.

Thanks

 

[ritcheyvs]

You could certainly try a t-stat; easy to do. More likely you had air pockets in the engine that prevented coolant from reaching all the hot spots. Typical water pumps just move water around and will not "lift" it any significant distance. So air pockets probably prevented coolant from circulating until it sloshed just the right way.

 

[jabelding]

I wouldn't run it much until you get it fixed you can do a lot more damage to the engine like warping the heads or hydro locking a cylinder it is definitely a head gasket and not a thermostat.

 

[adventure bob]

Whats the release pressure stamped on your radiator cap?

 

[Roscoe294]

Bad head gasket Thanks for the help guys. It fixed and up and running