Hydraulic Cooling/Blower Fan not Spinning, first steps?

[DPReef]

Bought a used Bobcat Skidsteer T650, was driving around to do some grading on my property and it overheats right when I hit a load of dirt.

The hydraulic cooling/blower fan doesn't turn on! Sprayed it with a pressure washer and cleaned out dirt that was below the radiator. I can spin the fan by hand but upon startup or letting the engine warm, no fan operation!

What could this be? Fan motor or hydraulic system? My loading arm and bucket seem to work , operate, and hold fine so I assume its not a hydraulic system issue. Do'nt see any hydraulic leaks and it seems filled to 3/4 the way into the "operational mode" How do I test the fan moter?

 

[brdgbldr]

I am not familiar with your specific machine and I know there are several different hydraulic fan motors used.

First make sure all of your fuses are good.

That being said, check the wires to the solenoid coil (or coils) on the fan motor. Make sure you are getting power to the solenoid coil. If you are getting power then your solenoid coil may be bad or the valve may be sticking.

 

[DPReef]

I went and checked all the fuses, and none were bad (check for continuity only right?). Below is a picture of the fan motor, that #1 is just the charge line.. The motor housing has two electrical connectors. I guess one is for the solenoid #23 and the other is the sensor #27? Do I just check to see if that line going to the solenoid has 12V or something? Not sure how that proportional electronical solenoid works

 

[brdgbldr]

Check for voltage. I'm not sure what the voltage should be on your machine at that point.

Also, check the temperature sensor for the fan. Like I said, I am not overly familiar with the T650 but if the fan is variable speed it must have a temperature sensor somewhere that controls it.

Is machine throwing any codes?

I really hate electrical problems.

 

[DPReef]

No machine codes. So i went out there and turned the engine on, used a wrench to spin the blades (not with my fingers) and it started going! Drove it around the lot and the fan did spin faster. Shut off the engine, restarted still "stuck". Once I give the blade a little movement the hydraulic motor keeps going.

At this point it can't be a fuse or electrical, I'm guessing its either the fan motor or fan. Called bobcat, they said to replace the whole thing (what other advice would they give). Not sure if something is breaking dow in the motor or debris is in there, my next step is to flush the hydraulic system and check filters and make a call if I try to see if that fixes before I replace the motor. Motor + new hose kit $2k...... ouch.

 

[brdgbldr]

Definitely change out the filter on the fan. Cut it open and see if there is any debris that looks worrisome.

I'm not sure, but it could be possible that the filter is so clogged up that it isn't allowing enough pressure by to get the fan moving. They do normally have a bypass but that can also get clogged. Kinda a long shot though.

Another thought, is the motor shaft spinning but not the fan blades. It looks like there is a hub that the fan blades bolt to. But the hub is held on to the motor shaft with just a nut. I do not see a keyway so I am not sure if the motor shaft has a flat on it or the nut just holds it on with friction.
One of the motors I looked at has a tapered shaft, meaning the hub is held by friction. The problem is that getting to the motor shaft nut normally means removing, or at least unbolting and moving, the radiator and all the other coolers above it.

If you can spin the fan by hand, without too much resistance, the hub nut is probably loose or missing.

 

[DPReef]

when i spin the fan, it's definitely not "loose" but I will take a look if there is any chance the shaft is spinning and the fan is not. When I spin by hand, there's definitely a fricton of some sort like a motor/gearbox am sure it's not free spinning.

 

[foton]

I think you have it narrowed down to either a lack of flow problem or a worn hydro motor. I wish I could tell you how to proceed from here on testing without just replacing parts and hoping you got it right, but as a question does it seem that when you spin the fan it comes up to the rpm you think it should be spinning at?

 

[DPReef]

Follow-up. So I replaced the charge filter which was really dark, didn't see any metal shavings, flushed hydraulics from the fan to reservoir with new fluid, cleaned the fan and added some silicon grease where the shaft meets the motor.

Fan starts moving on start-up and spins much faster than it used to when I would "kick start it". Thanks for comments everyone.