New Viscous coupling.

[louisoliver]

had my air con refilled the other day and was told my aux fans don't work and my viscous fan is inefficient. Bought a new viscous clutch and fitted it. However it doesn't spin freely when the engine is cold like the one I removed and if I rev the car when cold the fan gets loud around 3000 rpm is this normal and do these things take a while to bed in. Although the new clutch (made by sachs) is slightly different in appearence to the merc one i removed. The dimensions of the face mated to the fan pulley measures up the same. I don't quite know how these things work so thought I'd better check.

 

[Myros]

it should be free when cold

and coupled when hot. With a bit of gradation in between. I don't think the current weather is going to tip the coupling into thinking it's hot. Definitely something wrong there.

 

[louisoliver]

Thought it didn't seem right. This is the second one I've fitted. The original one I was given was a non german copy part. That had the same problem. Took it back and paid extra for the sachs one, but still same fault. Is it true these things should be stored upright and maybe that;s why Ive had two duff ones, or am I the duffer fitting them wrong can't be rocket science surely! Parts came from KMS in birmingham. Thinking of asking for my money back and resorting to dealer prices.

 

[FIBAMAN]

It depends what you mean by free, even when cold, there is some drag so the fan does rotate to a degree even when the engine is stone cold.

 

[louisoliver]

No movement at all the fan is locked tight to the fan pulley only movement is if I pull hard enough to make pulley slip against the belt

 

[television]

http://www.mercedesshop.com/Wikka/OM606ViscousFan

 

[Myros]

well found Malcolm

and what a great how to as well.

 

[television]

and what a great how to as well.

I have about 40 of them but I dont know what to do with them

 

[Myros]

you could do worse than what you already did

that is, slot it into an appropriate thread like this one. At least it'll pop up on searches. That's what I did with that 210 pixel thing i found.
Maybe some of the others can give us a hand getting them into the diy bit.

 

[louisoliver]

Hello, went out this afternoon to have another look started to turn the fan and it was a bit stiff but moved separately to the pulley after a few revolutions it became steadily looser. Seems it may of needed a little time to settle in .....I hope!

 

[television]

you have to allow for the air temp on a warm day