So I get home from a 200 mile trip in my 85 22RE and park her in the garage. Come out to take it to work in the morning and there is a "glob" of dark grey, thick, totally odorless fluid directly under the middle of the radiator area. Got a light out and looked around and it looks like this mystery fluid is all over the ends of the fan blades and has been thrown over the front of the motor and the steering stabilizer, etc. Any ideas what this stuff is? Could it be coming from the fan clutch? Thanks for your guy's help!

 

Sounds like the fan clutch, they norm. just leak slow, you see alot of dirt sticking to it?

 

Very well could be the silicone fluid in the fan clutch is leaking out. New it is clear, but with age the fluid could be dark as you describe. Does is feel slick to the touch like you would exect from silicone?

www.partsgeek.com has new AISIN fan clutches in the $60-80 range. Your could try refilling it, but most likely the seals/gaskets are shot and a new one may be the better option.

 

Acctually it feels exactly like silicone. That must be it. I had no clue that thing had any fluid in it. I just put a new alternator on a few days ago. Could I have got the belts to tight?

 

Once the silicone leaks out, the fan clutch will not function properly.... [edited out incorrect info after looking at fan clutch...belts mount behind on pulley as Rock Lizard points out].

 

Tight belts have nothing to do with the silicone leaking from the fan clutch. The belt behind the fan drives the pulley that drives water pump and is not connected to the fan clutch.

To prove this to yourself, with the engine NOT running, grab one of the fan blades and turn it--notice that it spins easily. If the fan were directely driven by the v-belt on the water pump pulley, you could not turn it by hand. OLD engines used to have direct drive fans with no clutch. Now fans have clutches for better MPG.

Anyway--the silicone can be easily replaced. Buy the silicone at the Dealer or find at Auto Supply like Napa, etc. No need to remove drive belts, but you need to remove the fan housing (two part plastic cowl) connected to the radiator. Remove the fan and clutch together, remove the fan from the clutch, take out the several small bolts that hold the clutch housing together (may need impact driver to do this--they are tight!), clean out the inner cavity where the silicone goes, then fill with silicone. Put everything back together and drive on! This is an easy job--even I can do it!

 

Agreed....I was having a brain fade above and have edited my post accordingly.

Fan clutch rebuild guide: www.4crawler.com/4x4/Docs/FanClutch.pdf

 

I was thinking to hard as well as I was just under there spining the fan by hand before I wrote this up....... Thanks for the help guys! I will knock it out tomorrow