komatsu pc200lc-3 hydro fluid heat

[papa_twebb]

My 200 will over heat when working . I can stop using hydraulics for a few minutes and it cools down. radiator and hydro cooler is clean enough to see thru. It seams as if hydro fluid is too hot. IT takes about 2 hrs for it to get to hot range. Replaced hydro element, old one looked ok. there is also a strainer in hydro tank, could it also restrict flow. Does not over heat when doing light work but will when digging. baffles are ok around rad.The 1/8 plug is out in housing between engine and pump. Water in rad stays full. I have not checked thermostat. Would removing therm help. Hydro fluid tank is full. Air filter is clean. Fan blade has small notches in end of blades where it had set on shroud before replacing engine mounts. What could it be, what am I overlooking.
Thanks for any help!!!

 

[lantraxco]

My first guess is your pump pressure is set higher than some of the relief valves they do get weak over time. If the oil is flowing over the reliefs instead of reaching high enough pressure to destroke the pumps you build heat in a hurry. The second thing that comes to my mind is internal bypassing in the pumps. I'm not that familiar with Kommie hoes so I'm just making suggestions for general hydraulic systems.....

 

[Delmer]

Most/some thermostats close off the bypass as they open up, so you don't want to remove the thermostat. You can take it out and test it, or use a temp gun to check the temp of the water going into and coming out of the radiator.

Clean enough to see through the radiator is a start. Can you see that the whole thing is clean while looking through it? Fan belt?

 

[John C.]

Maybe you should check some cycle times. Stretch the stick all the way out, open the bucket and set it all on the ground. Set the throttle at high idle and the panel in H mode. Lift the boom at full speed till it tops out. The time should be around 4 seconds. Let us know what you get.

 

[papa_twebb]

I got this machine about 3 yr ago. It has been converted to straight throttle from auto decel before I got it. I usually run 1/2 to 3/4 throttle . I have never used mode switch I guess I'm thinking it only worked with auto decal. Should I change switch mode. Added an aux fan in front of hydro cooler yesterday,also hydro fluid was at high mark but added 5 gal aw32 anyway, thinking it may help disapate heat. Used it today for about 4 hrs pushing over trees and stacking. It never got to red until I was digging a very large pine stump.I sat boom down it cooled down 2 notches in 5 to 10 minutes and never got back to red. Engine fan is mounted solid to crank pully, but belt pulling water pump is a little out of line to alt. If you use glove and try really hard you can turn w/p pully on belt. I will try to fix alt mounting to align belt and get tighter. Thanks for the replys.

 

[toreed47]

I have a pc200lc-3 that does the same thing have not found problem yet. I sealed the air space around the rad so all air has to pass through it helped a little took the rad off and had it cleaned still heating when you use it hard in hot weather. If you find out whats wrong with yours please let me know. Thanks Thomas

 

[papa_twebb]

I think I have found the problem. Its too simple to ever think it would be the trouble. The cab heater shutoff valve at the thermostat housing was turned completely open. I closed the valve and it does not overheat now. The heater gets hot water from them hsg and returns it to lower neck on radiator and back into water pump without going thru radiator this was slowly raising temp. How I found this is by removing shutoff to add a manual temp gage. I had cleaned rad and checked water pump and removed thermostat and it was still running a little too hot. When we removed valve we had to shut it completely to stop water leaking. With manual gage installed next to original went to get it hot by working it but it would not even get to middle bar on original gage and only 180 f on manual gage. So I sped it up and started digging and really tried to get it to warm up but it would not. I worked it hard for 3 hr and it still ran cool. Toreed47 if you have a shutoff heater valve close it and try it out. Engine and hydraulics stayed cooler. Post if it fixes your problem.

 

[lantraxco]

Well now, who'da thunk that? Great information for anybody with a heating problem on a cab machine!

 

[SterlingR]

One other thing on the -3 machine to pay attention to is the foam insulation around the radiator.