Fan Hub Service (1 Viewer)

[beatle_bayly]

Does anyone know the correct quantity of silicone fluid required to correctly service a viscous fan hub? Or the method to ensure the level is correct?

I've heard:

• 2 bottles,
• 3 bottles,
• lay it flat and fill the reservoir half to the brim, and
• hold the reservoir half vertical and the fluid should sit at the bottom of the centre hole........

I don't want to overfill and have the hub locked up unnecessarily.

 

[excessive]

i think the only sure fire method would be to carefully measure what comes out of the old one. I serviced mine in my 80 series many years ago, i remember putting it in the oven for a few minutes to get the oil heated up, and it came out easily. i dont remember how much I used

 

[beatle_bayly]

i think the only sure fire method would be to carefully measure what comes out of the old one. I serviced mine in my 80 series many years ago, i remember putting it in the oven for a few minutes to get the oil heated up, and it came out easily. i dont remember how much I used

Thanks mate.
Two things though:
1. Shouldn't the fluid become more viscous at higher temps (to add resistance within the hub at high coolant temps)?
2. The only reason I'd be replenishing the hub would be if I suspected the fluid was depleted, therefore I couldn't rely on the existing quantity as a guide.

 

[nissanh]

Here is a great video about the fluid action inside the fan clutch.

 

[Trunk Monkey]

fan clutch fluid replacement

Pulled my clutch on my parts truck and it is a aisin. Everything I am reading tells me it holds more oil but I didn't find any numbers. Any recommendations on how much oil to fill it with? Sent from my Nexus S using IH8MUD

forum.ih8mud.com

 

[beatle_bayly]

OK, so it's not the fluid viscosity at rest that provides the 'friction' to lock the clutch but rather the "unique non-newtonian shearing characteristic of the silicone fluid." Got it!

But still looks to be quite experimental in determining how much fluid I need. It seems the fluid breaks down rather than leaks out so measuring the existing fluid quantity looks to be the best method.

Mine is an Aussie-spec FTE and Toyota only list the one fluid for the hub (10,000cst?). When I requested the quote Toyota quoted 2 tubes, so 36ml total. I think I'll just do some more testing of the fan at operating temp to confirm it's locking up before I think about opening it up. The car is getting a new waterpump, radiator, all hoses and thermostat as a half-million KM birthday present.