I hope everyone is happy and well. I thought I'd share my experiences of repairing the Fan Clutch on both my ML320 trucks: one 1998 build and the other 2000.
In traffic I had started to notice temperatures creeping up and around the 95C mark and thought this was a little too high. On inspection I discovered a couple of issues:
- The Fan clutch
- The coolant expansion tank (for another thread)
The fan clutch was not operating correctly, one could tell by any number of markers:
- The fan would spin for several/many seconds after the engine stopped
- The fan could be spun with very little resistance by hand
- The fan could be stopped with a rolled up newspaper with the car at operating temperature
A replacement fan clutch assembly form the dealer was several hundred dollars, but there were replacement clutch assmblies on ebay which one could buy quite well around $60-100. Anyway it was a weekend and I wanted to do something about the fan clutch now.
I read the few fan clutch repair threads and webpages that dealt with refilling the fan clutch with new oil. As it turns out (or so the story goes) Toyota had sold some vehicles whose fan clutch had no oil inside them due to a manufacturing fault and so was forced to repair these vehicles, by refilling them with oil at their dealerships. This meant that they had to maintain inventory of the oil. It was a Toyota part 08816-10001
and was a 10,000 CSt oil- silicone oil I believe. So off to the dealership on Saturday I went and paid my $10 for 18 ml of oil.
All the repair threads I've seen deal with removing the copper coloured bimetallic strip on the fan clutch to get access to the tiny actuating piston, which once removed gives you access to a tiny 3mm diameter filling hole.
I attempted this, but found it was difficult to cleanly remove the clips holding on the bimetallic strip and also to heat and cool and also spin the fan in order to drip feed oil in the tiny hole to attempt to fill the fan. I did remove the clips and eventually attempt this method, but is was very slow and to my mind ineffective.
I decided to try something completely different by modifying the fan clutch to provide a filling hole for the oil to make the process FAR simpler and serviceable in the future.
The following posts show this in photos.