Bobcat 5600 mystery overheat

[pajibson]

Just did some work on a Bobcat 5600 to include replacing the front seal on the hydraulic fan motor. Now the customer says if the use it for 45mins to an hour it'll start getting warm or overheat. No signs of hydraulic leaks cooling systems is full and doesn't leak. Spent an hour last night pushing snow around with it (same thing they use it for) and it didn't even get half way to hot. But its done it two days in a row on them supposedly. Any thoughts ideas or suggestions anyone?

 

[crewchief888]

most toolcat overheating probelms i've seen have been due to a plugged up cooler/radiator.


:drinkup

 

[Mobiltech]

Does the fan run the right speed?

 

[powerjoke]

i'm with mobiltech. mine was a nightmare till we figured it out, turned out the fan was never hitting high. mine was a turf model so it had the screens over the coolers and it never plugged

pj

 

[powerjoke]

you know come to think of it, we continued to fight a problem after that and if i remember right the drive controller went bad and it had the front axle running slower than the rear and fighting against itself.

pj

 

[pajibson]

well the overheating problem is apparently intermittent (yay :Banghead) its never overheated on me but it has on the owners. One of them throttled it back a bit and didnt have a problem. The other one got in and drove it for a bit and it did.
Like I said I did just have the fan motor out and put a new seal on the shaft. None of us have heard the fan kicking on since then so that is where I would be inclined to look. waiting for the hydraulic and electrical diagrams to be delivered so I can dig in. They did take the cooler screen out and power wash it and the coolers.So I dont think its an airflow issue. They (the owners) are thinking something like coolant flow (sticky thermostat?) but that still leaves them with no fan drive. It just kinda spins like its being lazy. Not really driven at all.

 

[powerjoke]

didnt some of the first ones have a overheat issue ?....... this thread has got me to thinking about mine, and i remember we fought overheats all the time...... for the life of me i cant figure out what the dealer did to straighten it out, is there a sender or a sensor on the fan motor? that's ringing a bell with me for some reason and i dont know why..

sorry for the totally un helpfull and rantfull thread but it's all i got lol

pj

 

[pajibson]

There is an electrical connector on the pressure relief valve on the hydraulic fan motor yes. according to the wiring diagram there is a temp sender on the engine that runs to the controller. I found numerous threads on a different forum about the over heat and most of them ended up being crud between the radiator and the oil cooler. not the case here. Ran it for 2 hours last night @ 2500RPM trying to break up the ice on my street and the base of my drive way and the gauge never even made it to halfway.
So I really am starting to wonder about a thermostat issue. But that still leaves me wondering about the fan motor that nobody hears kicking on when it has over heated. there was also some mention about software updates in the other forums. Your responses aren't UN-helpful, we're just trying to talk through what someone says is a problem.

 

[crewchief888]

the very early 5600's had overheating issues, software upgrade solved the problem.

with the machine running, unplug the electrical connector at the fan motor, it should default to high speed, if it doesnt, i'd guess that theres a problem with the motor itself.

:drinkup

 

[pajibson]

Funny you should mention that crewchief. I did exactly that(unplug the connector on the relief valve on the fan motor) the other night. It did not default to high speed so thats what I was kind of wondering. I have to big problems now no 1 is that I dont want to sell these guys something and have it not fix the problem. No 2 is that I havent been able to verify the problem. Try as I might I cannot get this thing to get hot for me.

 

[pajibson]

so I did clean out all the crap between the radiator and oil cooler and verified that the fan does drive when you disconnect the connector on it(just not as hard as I thought it should) So I guess the next step is give it back to the customer and see if it does it again. I'll keep you posted. thanks everyone for all the help.

 

[crewchief888]

the fan should ramp up to high speed with the solinoid disconnected.

i would replace the fan motor


:drinkup