Checking the fan clutch
 

I own a 1999 XJ with the 4.0 auto and was curious how to check the radiator fan clutch? Should it move freely with the proper tension on the belt. I'm in the process of changing the water pump and t-stat and noticed the fan moves freely. Any thoughts? Also, I'm having trouble locating the metal hose or by-pass tube that comes from the water pump to the rubber hose going into the firewall. Is this going to be a stealership part?

Thanks

Fan clutches slowly degrade in performance over time/miles....+/-$35 buys a new one at virtually any auto parts store.

We couldn't find the metal tube locally....had to be ordered. A brass 3/8" MNPT X 5/8" hose barb nipple from just about any hardware store works perfect. The 5/8" heater hose needs to be a little longer.

Pepboys has the "carded water pump inlet tube" in stock near me. Per has theyll have it if theres one in your area.

-Taylor

Mine seems to have the same moderate resistance hot or cold. (best as I could feel). Since it hasn't been a noticeable problem in at least 10 years, I'm in no hurry to fix it. I do wonder if it's affecting my MPG.

when your engine is warm the fan clutch should be really stiff, so pop the hood when its warm and idling, then have someone shut off the engine. if it spins for a while as if its cold then its getting worn out.
also if you dont have a over heating problem dont fix it if it aint broke ;)

"I do wonder if it's affecting my MPG."

Yeah, its helping it.

Yep, don't ever change any fluids too soon or do any preventative maintenance in anticipation of something breaking.:whistling2: This time of year we're just about finished with the "heater don't work" threads and the start of boo-coos of "overheating" threads is just around the corner.

General Colin Powell:

“If it ain't broke, don't fix it' is the slogan of the complacent, the arrogant or the scared. It's an excuse for inaction........"



Think about it.......and maybe raise the hood occasionally.

NAPA water pump inlet tube-NOE 8257002

I hope you're not trying to call me arrogant and scared behind your mighty keyboard....

If you have any doubts about the part just replace it. Dont do it just because the internet says to

Supper cool tip on checking the viscosity of the fan clutch fluid. I didn't think of that! (watching after shutting off). :notworthy:

Ha! Too true! Booger for you though DJB, while we are on the lake, you will be swamped with overheating and AC posts! I Think I'm ready...that lower hose...will tell me in August.....

Please clarify.

My '96 H.O. six runs cool - never a problem, once I bleed the air in two cycles. However, the fan clutch, after 17.5 years and 157K miles, does not have much resistance at all, either hot or cold, and also has a looseness. When I grab one of the fan blades, it moves front and rear about 1/8".

I realize that the increased drag from a stiffer clutch would rob some HP and MPG. However, even though the car ran great for a highway run to the Delaware beach from Northern Virginia and a run to Gettysburg yesterday, cooling capacity seems like a good thing.

Is replacing the fan clutch a good idea? Do I need to remove the belt or radiator to do it?

Some guys are more into "preventive maintenance" than me. I always carry my tools and sometimes plan long trips when the stores are open. It's your call. I rarely can something that seems to be working fine myself. Of course I lube it and change the oil every year, weather it needs it or not.

On my 90 I'd need to pull the air cleaner and E-fan to get the belt loose. Then since the fan is bolted to the clutch, I'd remove the fan shroud and fan to get at the clutch.

Mine is at least 12, and likely over 14 years old. I regularly climb a steep hill in hot temps with mo problem.....That's all I've got! :)

Part of my reluctance is because I don't trust that "new parts", are made as well as the ones I have. Trucken strong at over 275K! :sweatdrop:

Forgot to mention - also lost the fan shroud, years ago. No big deal.

I know what you are saying about old parts vs. new. My clutch is the original, with 157K city miles over 17 years. I've been told that a replacement might not last but one quarter that time.

When I was wrenching on Kawasaki motorcycles years ago, the service manual said, like you, "If motor runs, why tune?"