mitsubishi mt1401d getting hot after hour of use

[littleblue23]

hi bit new to this. I have a Mitsubishi mt1401d and don't know why its getting hot plenty of coolant. and does it after an hour of use. don't know if its the water pump or thermostat could be a head gasket. but no bubbles in the radiator. Just need advice before i pull the water pump off it

 

[oliver28472]

Take a good look at the radiator. Have you recently bought this tractor? I would pull the pump last. Normally, go for the radiator or thermostat first, then the pump. My 1450 has a 3 cylinder in it and it was starting to overheat while mowing. I had the radiator gone through and that stopped it.

 

[littleblue23]

ive had the tractor for three years now. and never got hot before. ive taken the radiator out before and had it flushed and tested nothing was wrong than. Haven't checked the thermostat.

 

[oliver28472]

Some have found out that there was no thermostat. I made screens to go in front of my radiators and that helped. Good luck. If you wind up taking the water pump off, take it to a good auto parts store so they can send it to a rebuilder. That will take a couple weeks but will be cheaper than trying to buy a new pump.

 

[Ilikeurtractor]

If you have a infrared temp gun, shoot both the top hose (supply to radiator) and bottom hose (return to engine/pump) and compare the readings when it overheats or after it's warmed up. If you don't have a temp gun you can feel them with your hand but I'd recommend spending the $25-40 on a spot temp gun as they are pretty handy and a lot safer (and you can check hoses from a distance instead of sticking your hand around the engine!)

There should be a pretty good temperature difference between the top and bottom hoses (20 deg F at least). If there is little difference and both hoses are hot (over 190 deg F on the bottom hose) it's probably the radiator. Other results indicate the thermostat or flow issue with the system/pump (but likely the thermostat not opening).

 

[oliver28472]

Here's a couple more points, if you take the pump off, look it over pretty good. If it is still tight and not leaking, look at the fins. If they are still good and the bearing and seal are tight, then the pump should be OK. I installed a gauge on mine and still use the light. There was an allen plug on my pump that I removed and installed the sender bulb.

 

[Ilikeurtractor]

Make sure your fan belt is tight too since if it's loose enough, both your fan and your pump won't be spinning fast enough to do their jobs.

 

[caferacermike]

On my new to me Beaver, I found that the radiator fins were packed full of seeds and "chaff" (love saying that now that I've learned about it). I pressure washed the radiator until I could see through it. When I first looked at it, you couldn't see through it at all.

I also figured out, I was using the wrong PTO speed for the implement. You've owned yours for a couple of years so I doubt that is your issue, but might be good for future readers.


You could drain the oil and see if it has been contaminated with water. That would be a head gasket or crack.

 

[littleblue23]

Well I've had a look for the thermostat. oliver28472 you were right on there being no thermostat. Pulled the radiator off and pressure cleaned
fins and flushed it out. pulled the water pump off and the bearings and propeller were fine. so put a new seal on it. And than had a look at the head well thank god nothing was wrong there. No oil in the water and no water in the oil. reassembled it. cleaned most of the gallery's and had it running for about four hours. and didn't get hot going to make screens for it now just keeping an eye on the temps now.


well Caferacermike early days i put a tacho on the pto and got some readings so about 1900 2000rpm in pto 1 is 540 and works well with most of my attachment.


thanks for the support every one

 

[oliver28472]

I don't know if your engine block has a coolant drain, mine didn't. I found a plug and replaced it with a petcock so whenever I change coolant I can get it all out. Mine (3-cylinders) were on the right side near the oil filter.