Kubota L4240 is overheating

[oranget34m]

I've had my Kubota L4240 for a few years, it's usually works great, without drama. but now, it's overheating and idk why.
it has water, oil, and starts easy and runs great at first, but after 20 minutes it slowly overheats to 6 marks on the temperature gauge.
It continues heating if I don't shut it off. usually I give it a break and then restart. I don't see any water or oil leakage, nor is steam visible.
It is a 2013 L4240 and has a front end loader and a 60" mower hanging on the back.
what should I check next? anyone ever got the same issue?

 

[load3rpro]

Had a similar experience with my old Kubota, discovered that the radiator fins were packed with dust from mowing. A quick clean really helped

 

[Nexo]

This happened to me once after I had the loader running all day the thermostat was sticking. I replaced it and the overheating problem went away.

 

[TractORange]

My L-series also used to heat up after about 20 minutes and it turned out to be a weak water pump. I changed it out and now it’s been working perfectly.