Radiator fan motor

[JF1957]

Hi, i have a 1995 Coachmen Destiny with a MM2242 Spartan frame and a 6CTA 8.3 Cummins diesel engine and a side radiator. Can somebody told me how is that radiator fan motor work, is it hydraulic ? Pneumatic ? There is two about one inche hoses that goes in the motor, what make that motor start ? We've been on high moutains on our last trip and the engine temperature reach 225 degres climbing those mountains. I don't think that the motor is working well, is there a way to test it ?
Any in will be appreciate, regards.

[mackwrench]

Then fan is hydraulic driven. The same pump that runs your power steering provides pressure for it. The fan is controlled by a temperature sensor.

If the engine is not running hot until you really load it, I would think the fan is working properly otherwise it would run hot on flat level highway.

When is the last time the radiator was cleaned on the outside? These are known for picking up leaves, straw, grass etc.... And clogging the fins causing a air flow restriction though the charge air cooler and radiator.

[JF1957]

Originally Posted by mackwrench

Then fan is hydraulic driven. The same pump that runs your power steering provides pressure for it. The fan is controlled by a temperature sensor.

If the engine is not running hot until you really load it, I would think the fan is working properly otherwise it would run hot on flat level highway.

When is the last time the radiator was cleaned on the outside? These are known for picking up leaves, straw, grass etc.... And clogging the fins causing a air flow restriction though the charge air cooler and radiator.

So has i understand you, it should have a selenoid valve somewhere thats open to let hydraulic fluid start the fan motor running ? Do you know where i can find the temperature sensor ?

Radiator looks very clean btw, thanks for the prompt answer mackwrench.

[mackwrench]

I'm not sure where your temp sensor is, it should be on engine near upper radiator hose / thermostat area, you'll need to check Cummins on that. If you trace the hydraulic lines from the fan motor you may find the flow control valve solinoild.

Run the engine at high idle in you driveway, around 1400 rpm, go back there and see if fan comes on, you'll hear it as well feel air moving though radiator from side of coach. It may take a little bit for fan to come on since thermostat will open 1st. I'd run it 10 or 15 minutes.

I've had people tell me radiator is spotless just before I pull a large bird nest from them.....
My point:
Just because radiator looks clean don't mean it is, you'll need to lay under and look up inbetween charge air cooler and radiator. Take a garden hose and back spray though the radiator see if anything yukky comes out. You can buy some condenser cleaner from Home Depot and use that for cleaner, but no pressure washer, home hose psi only.

If the fan does not come on at all / ever it would run hot all the time. Not just when going uphill.

[Gary RVRoamer]

you'll need to check Cummins on that.

Actually you need to check with Spartan on that. Cummins has nothing to do with the cooling system outside of the tubes inside the engine itself.

[mackwrench]

Originally Posted by Gary RVRoamer

Actually you need to check with Spartan on that. Cummins has nothing to do with the cooling system outside of the tubes inside the engine itself.

Thanks for clearing that up......what I wanted to say is you can't check with mackwrench on that.....ha-ha