Yanmar VIO55-5B running hot

[1974Northerner]

Good evening

I have been trying to get my excavator to run cooler, it will gradually heat up beyond 200 if i work it hard
I have flushed the system several times until it stayed clean
removed the thermostat
Replaced the Water Pump
System does not build pressure and also tested for exhaust in the coolant and its good
On the machine the fan pushes air out from engine through Rad, I question this but there is no way to change as far as I know
Any advise be greatly appreciated

 

[old timer]

Good evening to you too.

lets see if I can help, first, i would re-install the thermostat (preferably a new one)
4TNV,s are pretty reliable, rarely do they overheat.

Then I would look at the hydraulic system, is it getting hot? Use a I/R thermometer on the lines.

Also, be very particular about ANY debris in the cooler. Ran into this with a large excavator, at first look it seemed clean but I found that the corners and edges did not clear. Believe it or not, about a 1/2 inch around the edges was enough to overheat the hydraulics. Only way I found is to remove and have the cooler cleaned professionally.

Hope this helps.