----- Original Message -----
From: "Pharmanaut" <
[email protected]>
Newsgroups: alt.autos.volvo
Sent: Sunday, February 13, 2005 6:09 AM
Subject: Re: Electric Fan
I have the fluid clutch fan on my 240 but by the look of it it's seized.
The coiled spring on the front of the fan hub (I presume it to be a
bi-metal temperature sensitive device) is rusted and doesn't move. Is this
common? What would the benefits be of replacing it?
Pharm..
The bimetal coil on the front normally doesn't move at all when you try to
twist it. It controls a viscous clutch inside the housing - the closer the
clutch plates get to each other in the goo, the more coupling to the fan.
When you try to turn the fan with your fingers - with the engine off! - it
should turn smoothly with some slight resistance. It will fail eventually in
one of two ways - the silicone goo will leak out, causing it to become
useless; or the bearings will seize (often not quite straight) and the fan
will vibrate. In the first case the engine tends to overheat when idling in
hot weather; in the second case it is bad for the water pump. If your engine
is overheating in hot idling, and you test the fan and find it is still
turning freely when the engine is hot, you've found the culprit.
I've replaced the coupling on our '85 765T twice, both times with
aftermarket couplings from NAPA that cost almost $100 US. The first one
lasted barely a year before it seized and the second has been good for the
last 4 years. IIRC a genuine Volvo part was about $150 US, and I might have
been better off doing that to start with.
Mike
