Hello,
I was recently surprised when an mechanic at an A/C shop demonstrated a broken cooling fan clutch by sticking his finger into the fan blades with the engine running. The fan offered little resistance and came to a stop.

I gather that the clutch can be separated from the fan and replaced.

Does anyone have any info of the steps involved in replacing or even better, repairing the clutch?


Thanks.

I would get a little better diagnosis than that first. The Volvos you usually cannot stick your finger in without getting it chewed off but most BMWs you can just about count the fins as they go by, no b.s. When I function test a clutch/cooling system I block the air flow across the radiator with a piece of card board, lock the throttle open with a ball point pen at about 2K, put a thermocouple underneath the edge of the upper rad hose at the t/stat housing and watch the temp climb. The fan clutch should engage by around 210-215, noticeable by the roaring it makes when moving air, now remove the cardboard and watch how fast it returns it to normal operating temp (190 or so) and make note of when it disengages.

Now your average Joe probably does not have a thermocouple and a Fluke meter at his disposal but you could do the same thing and just watch the temp guage and watch the motor for any signs of it starting to run hot.

Should you have to replace the clutch just:

Remove the top two fan shroud screws.
Lean the shroud forward and remove the 4 nuts in the front of the fan
Remove the fan
Lean the shroud back where it goes and reach in and remove the 4 nuts on the clutch.
Remove the clutch.

If you want you can even reach in and remove the 4 nuts on the clutch/water pump pulley connection and pull it out as an assembly fan/clutch and then change out the old fan onto the new clutch on the bench. Either method works just fine.

As far as repairing the existing goes I would not bother. Back in the early days of fan clutches they use to service them and replace the silicone oil that was inside of them or the clock spring on the outside but I think that is a dying art and most folks just hang new.

Mark

instructions to replace the fan clutch http://www.brickboard.com/FAQ/700-900/Cooling.htm#Thermostatic_Fluid_Clutch_Test
New fan clutch about $63 here:
http://www.fcpgroton.com/volvo700900heating.htm
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-------Robert, '93 940t, '90 240 wagon, '84 240 diesel (she's sick) , '80 245 diesel, '86 740 GLE turbo diesel, '82 Mercedes 300SD for sale