Yet nother fan,clutch water pump question

[DrM]

Hi!

So basically I had a friction clutch and the beautiful 400mm 5 blade on my 72 cs (manual ,no AC)but unfortunately something went wrong and after hearing weird noises opened the bonet and the fan centre where the bolts are mounted to the friction clutch was literally melted....was lucky enough the radiator survived and nothing caught fire...


I thoroughly searched the forums and came to the conclusion that switching to 9 blade and visco clutch is my best option but since the waterpump is also old I decided I will also get a new waterpump for the peace of mind.

I would kindly ask for a quick review of the parts I need

water pump
11519070760
fan
11521271846
visco clutch
11521723918

thank you

 

[tochi]

While your part numbers look OK, it may be preferable to order the eleven blade fan (11521723363). https://e9coupe.com/forum/threads/cooling-fan-upgrade.10468/ I also wonder if you need to separately acquire fan-to-clutch fasteners. (These fasteners and the pump gasket may be included with the ordered parts.)

I am more curious about the original mechanical clutch failure - and a photo or two might be instructive. Ordinarily, the clutch would slip - or lock up. Your situation suggests the clutch (and fan) locked, so that it was not free-spinning. Then, it contacted a stationary object, i.e., radiator or something adjacent. You probably heard the fan belt squealing. Unless you determine the cause of the fan damage, upgrading to an improved fan clutch is unlikely to prevent another unwanted contact. (First guess would be weak mounts (engine/transmission). Second guess would be a radiator that is not securely tethered to the forward bulkhead. )

As an afterthought, if you have a clearance issue that cannot easily be corrected by mounts or even a thinner radiator, you could always consider an electric pusher fan.

 

[sfdon]

Don’t forget a pulley…..

RealOEM.com - Online BMW Parts Catalog

BMW parts 5' E28 535i Cooling system-fan/fan coupling

www.realoem.com

at our shop we install fan clutches AND thermostats AND pusher fans AND temp senders to turn on that pusher fan. Just like BMW did starting in 1973.

 

[Ohmess]

I have a pusher fan mounted on the front of the condensor, with a temp sensor on the bottom of my radiator, just like what Don is recommending (indeed, I consulted with Don on the temp sender to use when I did mine). The pusher fan turns on (1) when the a/c is on, or (2) as a secondary cooling mechanism when the temp sender is tripped.

If you are mounting an electric fan to the radiator in lieu of an engine fan, which I think is what tochi is recommending as an alternative, that fan should be a puller, not a pusher. And if your car has a/c, you would want a two temp switch, with the puller fan going on at a lower temperature, and the pusher fan on the condensor set to come on at the higher temp on the temp switch (in addition to coming on when the a/c is on).

Also, if you go with a radiator mounted puller, a fan shroud is a good idea as it makes the fan more efficient.

 

[sfdon]

Excellent….