M42 Overheating...another one

[fresh_TD]

One more thing before I make an order. The radiator temperature switch doesn't control the fan clutch does it? Just the aux fan?

Controls the aux fan. The fan clutch is mechanical not electrical.

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[onesecond]

Thanks!

[onesecond]

So I replaced the fan clutch and the issue persists. Tried bleeding the system and the second it bled, it pressurized and a coolant leak happened at the bottom of the expansion tank. Same as seen in the picture in this thread https://www.r3vlimited.com/board/sho...nk+leak+bottom

Looks like I have an air leak with the tank. Ordered a new one but wanted to know, is there a way to drain just the tank and reuse the coolant (I know I know). Just don't want to do a full flush then realize I have more air leaks in the system and have to keep replacing the coolant

[fresh_TD]

So I replaced the fan clutch and the issue persists. Tried bleeding the system and the second it bled, it pressurized and a coolant leak happened at the bottom of the expansion tank. Same as seen in the picture in this thread https://www.r3vlimited.com/board/sho...nk+leak+bottom

Looks like I have an air leak with the tank. Ordered a new one but wanted to know, is there a way to drain just the tank and reuse the coolant (I know I know). Just don't want to do a full flush then realize I have more air leaks in the system and have to keep replacing the coolant

A "full" flush requires you to drain coolant from block, which you aren't doing. Coolant is cheap enough. Get what you need, to do the job correctly.

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[roguetoaster]

A coolant leak at the bottom of the tank can easily be a false positive as the coolant from the bleed screw leaks down there.

You can drain the system via the blue drain at the base of the radiator expansion tank. If coolant does not come out once the drain is cracked open you will likely need to completely remove the blue screw/drain and jab in the hold with something pointy to clear a blockage.

Just for fun, do the fan clutch test again and watch the brand new part fail. Basically, even new fan clutches that I have seen do seem to fail even with the engine at full temperature.

[onesecond]

I'm pretty positive of the leak on the tank as it came pouring out and didn't line up with the leak from the bleed. I will do the test tomorrow for the fan clutch and thanks for the heads up!

[onesecond]

Well there is a told you so, looks like I got a bad new fan clutch?

https://www.youtube.com/watch?v=LX923QRA2pE - after a 30 minute drive
https://www.youtube.com/watch?v=d8e7Dc9hwCU - just after turning it off

[jrobie79]

Well there is a told you so, looks like I got a bad new fan clutch?

https://www.youtube.com/watch?v=LX923QRA2pE - after a 30 minute drive
https://www.youtube.com/watch?v=d8e7Dc9hwCU - just after turning it off

by the looks of the 1st video it's toast

[onesecond]

Yeah, the new one is installed and it's running cool. Very happy now!