Avar928

This is for an early '86 928S 32V Auto.

I'm going to do some rehab on my fan clutch, refilling the fluid with silicone. My local Toyota parts store doesn't carry any of the silicone fluids (according to the manager, no one asks for it so they stopped carrying it). If I buy it online, it's $30 including shipping for two 18mL or so bottles. However, if I buy the silicone differential fluid (Team Associated 5457 Silicone Differential Fluid, 30000CST) used by hobbyists for RC cars, its a 59mL bottle for under $7 including 2-day free shipping (Amazon Prime membership). Viscosity are 10,000 CST or 30,000 CST.

Anyone have any luck with RC car fluid? How does it stand up to the engine heat? Is the higher 30,000 better? Any luck with finding a better pin to prevent leakage?

Also using LandSeer's nice pictorial post for re-fill, going syringe method and the whole thing looks simple enough - https://rennlist.com/forums/928-foru...re-fill-2.html

jpitman2

Didnt work for me....all got flung out promptly after startup. Maybe you can find a better seal for it. Have since gone electric .
jp 83 Euro S AT 55k

Avar928

Would putting some sealant on or around the pin ensure no leakage? Or would that mess the clutch up?

WallyP

At that price, it is certainly worth a try. The 10k would be closer to the original fluid, and would probably be better in everything except for heavy traffic in high temps.

jwillman

I also tried 10,000 which was immediately slung out. Now using dual electrics.

Others have had success.

Avar928

I think I'll go with the 10k RC fluid and use RTV to seal the seams to prevent leakage.

Landseer

10,000 IIRC was the thicker of the 3 toyota solutions. I used it and it continues to work well. I probably put a dab of silicone sealant over the tiny rubber seal beneath the bimetallic strip, then used a bit to help anchor the bimetallic strip.

autoslave

I did this last fall. I used the RC fluid and it stayed in for most of the Fall, this spring I had a mess on the inside of my lower chin spoiler.
I think it's internal seals which let out the silicon and all the RTV sealant in the world wont do it.
1, Why is this thing so expensive to buy new?
2, Couldn't one of you super tech guys invent a real rebuild process?

jpitman2

Many of us have fixed the problem with electric fans for a lot less money = more cost effective , especially with the crappy 5 bladed fan! Or you could adapt another vehicle's viscous fan - I did this with a Land Rover unit a few years ago.
jp 83 Euro S AT 55k

Jetdriver69

I went to an electric fan myself.

I used a FFDynamics fan I found on eBay. Works great and easy to install.

Very high quality materials and fairly low price. Keeps my 82 cool even in Texas heat with AC on.

Hold On

I used the 10,000. it worked great, takes a little time to put in but worked. It was 110 in Phoenix and the car kept its cool.

Mrmerlin

FWIW the reason the fluid is leaking out is due to the brass pin having damaged sides,
if possible polish the pin then after filling add a dab of silicone to the top of the pin head where its sticks out of the green seal face as Chris mentions.