seven

I am working on the a/c system on my 2001 cherokee..(Inside temp will not go below 60 deg) I had it running with the a/c on and was hosing down the condensor through the grill with a hose to see if their was any difference in the temp inside the truck.., I had the hose on and noticed that the clutch fan stopped while car was running?? I was spaying water through the grill through the condensor and I guess onto the fan on the pass side of car?? .When I took the hose off it it did start spinning again after about 30 seconds. with car off and engine warm you can easily spin the fan? Is this normal? Or do I have a bad clutch Fan?? I did a search and can only find information on the blower fan?/ can anybody advise me how to check the clutch fan properly?? Thanks Bill

BassMasterCHS

So let me see if I understand you:

The clutch fan on the passenger side completely stops moving while the engine runs?

It should not spin freely if it's hot after shutting it down. If you can spin it more than one revolution, it's junk. How old is the clutch?

The best way to test it is to use your hand to stop it while it's running.

Just kidding, don't do that.
It sounds like you're low on refrigerant if anything. Is your electric fan coming on?

seven

Thanks for the reply yes the fan stopped turning completly with the water from the hose?? I am pretty sure it is full of ref. the liquid line is dripping by the firewall, the spout on the bottom of the evap. box is dripping, the dryer is sweating and my gauges are reading 35 on the low pressure and about 200 on the high side?/ The truck is a 2001 with 90,000 miles on it history unknow but I did buy it with a blown engine and rebuilt it and was trying to recharge a/c system I did install all new gaskets or o rings and evacuate system before recharging..

F1Addict

There are no surefire ways of testing the fan clutch. My method involved listening. With the hood closed, let the engine idle until it reaches normal or above normal operating temps. With the transmission in Park, rev to 3,000-3,500 RPM, you should hear the mec-fan roaring under the hood. If you don't, time for a new one. I paid $42 at NAPA so they're not crazy expensive.

As far as I know, the fan is never supposed to "stop". The viscosity of the silicone within the clutch mechanism will spin it even when the clutch is fully disengaged.

freegdr

Cold engine easy to spin....Hot engine hard to spin...Tried and true method.

JohnEP

Water from your hose may have cooled the clutch, causing the fan to essentially "stop spinning".

I think it is a bit more complex than this... Seems like there is a 3-step process to the workings of the clutch: First thing in the morning, when the engine is dead cold, the mechanical fan sounds like a 747 taking off when I first get some RPM's on the cold engine. Then, it quickly dies down. Then, the fan will start to spin more rapidly again if the engine heats up enough... Of course, I might be completely misinterpreting these sounds. Anyways, a completely cold brand-new fan clutch does have a decent amount of resistance.

Agreed; but maybe, if there really is a 3-step process, a garden hose could cause it to "nearly stop."

I'm not so sure that you have a "bad" fan clutch; and that fan shroud is a real bear to remove (without the right tools). If you have the 4.0 with the weak (non-TUPY) 0331 head (not sure how you rebuilt your "blown engine"), then you are right to replace the fan clutch if ANY doubt.

If you do this job, I STRONGLY urge you to get the correct size (metric) ratcheting closed-end wrench with the flex head. This is what I used to get the lower bolts off the fan shroud: http://www.harborfreight.com/5-piece...set-60592.html.

Eventhough my fan clutch seems good, I am putting a new one on right now as I replace the water pump, eventhough I now have the TUPY 0331 head on my 2000 4.0.

JohnEP

F1Addict

I replaced my fan clutch last month after suffering from high temps, especially at low speed. Upon removal, I saw that some silicone was seeping from the face of the unit. This is a sign of possible failure. Two signs that it's working: Reduced underhood temperatures (yay!) and a noticeable reduction in horsepower (boo!).

I'll be switching to a dual e-fan as soon as I can afford it.

seven

Thanks to all for the reply`s I have a feeling that theory is correct about the hose cooling it off?? Seems fine did the checks hot and cold just going to keep an eye on it?? Then , I decided I would switch it out anyway with a know good one I had, kinda glad I did I think I might have found my problem with the a/c .. I am pretty sure the front seal on the compressor is leaking.. with the fan out of the way I took the plate off the front of the a/c compressor and sure enough their is a little dye on the shaft , It is odd though it is still blowing fairly cold and has been for the last two weeks since I filled it?? . I also put the manifold gauges on it and did not really notice any difference in the readings??? Unless my eye`s are just playing tricks on me.. but thanks again , going to see if I can change the front seal on the a/c compressor??

salad

Amusinglyy, that's very close to the FSM method for testing the clutch. There's of course taking measurement of exact temps but the actual test is "it should make a roaring sound"

F1Addict

I'm rarely 100% sure where the data I spew comes from. I might have been paraphrasing something I once read in the FSM although my reading comprehension is suspect, so I doubt it

It is amusing, though. One expects a scientific-based, systematic approach to the FSM, "It should make a roaring sound" is... well, not scientific.

jakecarder

Hey buddy make sure you do some research before you spend a fair amount of money on the e-fan swap. There has been plenty of guys that do junk yard doubles and even spend the great deal of money on dirtbounds triple set up and it fails. IIRC most all report temperatures greater by 20-25 degrees from where they started and some a constant 240. Most all end up going back to the mechanical fan. There has been a few that were successful with just the fans hence why there still being sold but it varies jeep to jeep. Ones that didnt get it to keep temps at normal operating temps sometimes had luck by adding an all aluminum 3 row radiator and wiring 2 of the fans to stay on all time and one for ac and over heat. But then again all of that is 4-700$ for equal performance or hoping it will be somewhat better. Honestly from all my research on all this e fan, radiator and cooling systems the best and most effective would be new mechanical clutch, proper fan shroud, aluminum radiator(2 row or 3 row depending on what's available and in price range but most importantly just being aluminum) and the biggest improvement would be HOOD VENTS. You might know all this and have done your own research but I'm just giving you a heads up if you don't already know. Don't hurt to say
I'm sorry SEVEN for the thread jack just trying to save him some headachs and who ever else reads this.
It does sound like your a/c system is leaking. Even though its leaking just a bit it could last a little while longer. I've seen some people have a small leak and it lasts a month to 5 weeks. They would just buy a couple cans and refill it ever so often and have been for multiple years. I believe that's bad for the environment tho. O-zone layer or something

F1Addict

Thanks for the heads-up Jake, I've done quite a bit of research and will be using a custom setup with two 16" 3000 cfm Hayden (or Zirgo) fans, one will be linked to the temp switch and the other (fan clutch replacement) will default at 25% velocity with 100% available via a switch in the cab. I know of several people who are using a similar system with significant improvements in cooling. My biggest disappointment in the mech fan is the amount of horsepower it saps, there is a very noticeable difference in performance. Total expense will be around $250, I'm willing to risk it.