2004 6.0 PSD F350 with 107k miles.
Engine temp is always showing normal, dosen't overheat or run hot.
Started trying to repair the AC.
Had the system flushed, Replaced, AC compressor and Aclumilator. Evacuated and refilled. AC blows cold. BUT.......
Pressures build when truck is at Idle. Water on the front AC radiator and all is normal. [system was cleaned and flushed OK, front raditaor OK] Fan clutch is turnning at idle and can easily be stopped with a broom. The end with the bristles.
My question is ....What type of Fan clutch is on my truck and how does it work ? Is it electronic, viscus or belt driven ? A detailed how it works would be cool. Right now I can see the fan spinning, it is not spinning at idle as fast as you would expect. It has an electrical connection mounted on top of the fan shroud.
And why, when I look up the replacenment part on different web sites do I get prices from $49 to $377 ? AC works for now, but will the not so fast spinning clutch fan kill this new compressor when I am sitting in traffic ? Or is this how the clutch fan is supposed to work.
Thanks in advance for taking the time answer some of my questions.<!-- controls -->

 

I think the fan is viscus. With a 6.0 that's running properly, you won't get the fan clutch to engage unless your towing something heavy up a long hill on a very hot day. When the fan engages it will sound like a dull roar. It usually won't affect your AC performance at all.

 

Should the fan be on when the AC is set to max ?
Is there a way to test the fan and force it to high speed by jumpering the elec connector on the fan showd. ?

 

The only time I ever hear my cooling fan start up is when I'm towing 8000 lbs +. I'm going up a mountain pass or a long hill with some grade and it's a fairly hot day. When it comes on, it sounds kind of like a roaring noise and it doesn't stay on very long. Never heard it with just the A/C,. max or otherwise. It's not necessary. As for the jumpering question; sorry I don't know.

 

You fanshould be viscus drive, when the engine is cold and its cool outside you will hear it run lik a cyclone when you first crank it.

DO NOT TRY TO STOP IT WITH A BROOM, one of these time the engine will be to cool to try this and the broom may very well hit the Space Shuttle or rip the hood off.

I think you are referring to like FWD cars that have an electric fan to cool the AC condensor. This is not the case with your truck. Your fan is belt driven and the AC does not affect it.

If you AC is building pressure at idle it may be the the AC condensor has debris in front of it like bugs, leaves etc. and NOT getting air flow.

It is not in the fan.

Try cleaning the AC condensor.

 

my roaring gets very load and sometimes stays on for a long time. any ideas?

 

my clutch fan comes on at the same exact spot every time. Towing the boat to the lake there is an incline followed by a big downhill at idle, followed by an uphill. As soon as I head uphill it kicks on like clockwork!

 

It is a viscous fan clutch that is computer controlled. Instead of the bimetal spring controlling the flow of the viscous fluid like the 7.3s used the 6.0s clutch is controlled by a pulse width modulated signal from the computer. It will only engage like said above if the temps get high, a/c has no effect on it.

I added a 14" pusher fan to the passenger side lower corner of the condensor (partally behind bumper). It is wired to a switch on the dash that I usually leave on in the summer months, but you could hook it through a relay to the a/c clutch power wire so it will come on with the compressor. It dropped my outlet temps by 10*F on max a/c and keeps head pressure down. That corner of the condensor is the last place freon goes before heading out to the orfice tube. I also added a ranger heater control valve and it dropped the max a/c temps by 5*F.

 

The repair has been completed.
The Fan clutch was replaced.
The AC still is blowing COLD, but most importantley the High and Low side pressures on the AC are rock solid. After two minutes, they settle down and hold within limits. No more high side pressure rising. Also for anyone thinking of trying this in the future.
You can NOT get the fan clutch out without removeing the fan shroud and radiator. [skip any cutting of plastic fan shroud tips you might see on the internet]
But don't feel too bad. Once you remove the rad hoses, upper and lower, trans cooler lines. [ Note: it is easier to remove the soft hose trans connector end ranther than the rusted connections at the radiator.]
Remove the plastic press to fits on the grill cover, and the plastic fit wire harness holders in front of the radiator. This makes about 2 inches of room. Just enough to get the radiator tilted front and up, to easily get the radiator out of the engine bay.
Also examine your replacenment part to figure out the direction of the fan clutch threads. If you will be trashing the bad fan clutch.
Place a screwdriver through the fan clutch sheild/water pump. To keep it from moveing. And zap it on the left side of the nut with a long air chisel. Three baraaps and you can spin it free with your hand. [baraap,baraap,baraap.]
Helpful notes:
Refill radiator with only Ford Gold Collant. And on the 6.0's the proper fill level is AT the Lower Level on the bottle. Not between high/low as most folks would think. That was a suprise.
Don't forget to top off and check the auto trans fluid when done. Mine took two glugs from the bottle. [Glug, Glug]
Also noticed. My AC compressor works whenever I : Run my AC, Run defroster, run heat on chest level setting. All suprises to me.
Hope this helps make someones job a little easier.

 

Also one final note. At idle the old fan seemed to be spinning slowly, I could stop it with the bristles on a broom end. You could almost see through the fan blades as they were spinning.
After replacing the fan clutch.
THE FAN AT IDLE IS SPINNING NOTICABLY FASTER, And really can't stop it with a brooms bristles. It does slow down, but picks ups speed noticably quickly. There is a strong breeze you can feel with your had between the fan shrowd and engine.

 

I had to replace the fan clutch on my '05 6.0 after about 20,000 miles, it would sometimes engage and stick on, it would put a major drain on the engine power.