Intro - Heauxmie the Bus

[Phreqq]

Hi wonderful Skoolie.net peeps! I'm Isaac, and last spring (2021) I bought my bus and have been slowly converting while using it for camping and road trips. This means conversion has been slow, but also our needs/wants are constantly developing as we come up with better ideas and realize what we really do want and decide what we don't really need.

Bus info: 1994 AmTran Genesis 36' 14 window Flat nose with DT408 and MT643.

Currently having some ~minor cooling issues I am trying to solve before going on a big road trip next month.

[Jolly Roger bus 223]

welcome.
for the cooling issues.
have you cleaned and flushed the radiator?
is your fan kicking in?
plenty of good clean fluid?

[Phreqq]

Originally Posted by Jolly Roger bus 223

welcome.
for the cooling issues.
have you cleaned and flushed the radiator?
is your fan kicking in?
plenty of good clean fluid?

Thanks for the tip! I am waiting for a new thread to be approved to help with diagnosis, but:

Drained, flushed, and refilled with Green+DCA and new coolant filter with DCA as soon as I got the bus. It had been occasionally run and sitting for ~5 years.

I can't tell if the fan is kicking in or not. I've read you should be able to hear it "roar", but I haven't noticed a big change in air/fan noise as it heats up. Opening the doghouse is quite windy. Someone gave the tip of getting it good and hot, turn it off, and the fan shouldn't be able to be moved by hand much if the fan clutch is working as it's supposed to. I haven't been able to try this yet.

The Radiator had a small (1/2") fracture/crack near the top which I brazed and JB welded over (first time brazing ever...). It seems to be holding up well, but makes me wonder if there are other small system leaks. Am I correct that if the system can't build pressure, it won't be able to circulate coolant? Or is that only the case if the leak is engine-side?

[Jolly Roger bus 223]

with that said you dont have an electric fan you have a vicious clutch fan.
go to youtube university to see how to diagnose the fan clutch.
i suck at explaining things online and do better hands on.
but if you up up to and or above operating temp you should be able to hear that style fan roaring.
just cause its kind of spinning doesnt meen the clutch is locked in and my first procedure for testing doesnt get shared for safety reasons.

[Veloc]

Clutch fans are simple to diagnose. Do all hand checks with the engine off. Some folks will test by grabbing the blades while the engine is running, but that's an easy way to lose some fingers. And, just because it's never happened before doesn't mean it won't happen next time due to how clutch fans operate.

Cold - should be hand spinnable, but with resistance. This is because it has a viscous fluid inside for the locking mechanism to work and that fluid will settle when the engine hasn't run for several hours. Engine running, should be no discernable fan noise, maybe a light roar and generate a light breeze.

Run the engine a minute but still cold - should be hand spinnable, and easier to spin. The viscous fluid will have been spun up inside the clutch fan, so there's no longer a big glob of it settled to one side. Engine running, should be no discernable fan noise, maybe a light roar and generate a light breeze.


Operating temperature - may be hand spinnable, but should be difficult to turn. Engine running, should be a little fan noise, roar should be a little louder, with a little more of a breeze. The viscous fluid has absorbed heat and is expanding, which is starting to lock the blades to the shaft.

Hotter than operating temperature - Not spinnable by hand. Engine running, should be a very loud roar. There should be a strong breeze, and you should feel nervous about sticking a hand in. The viscous fluid should have the blades solidly locked to the shaft at this point.

[Phreqq]

Thank you Veloc!!! Hugely helpful!

I feel like my fan clutch never goes past your description of normal operating temperature, but I've never gotten it above temp and shut it off to test.

[Phreqq]

My other thread for diagnosing the cooling issue was approved: https://www.skoolie.net/forums/f37/d...-new-post.html

Thank you everyone who has contributed!

[TheHubbardBus]

No, thank you, Isaac. You're a refreshing change from a lot of new accounts that disappear after asking a question, and/or never answer any questions they can provide help withn. I hope you stick around.