Fan Clutch Question

[Glennman]

While I'm working on my fan/radiator problem I thought I'd ask about the clutch mechanisms. I have what appears to be a 1/4" air line connected to the center of the fan clutches. Those go to an air switching mechanism that has a toggle switch on it. I've never really messed with it, except to see if it made any difference when I flipped the switch. I can't tell if it even does anything. I'm assuming that it would cause the fans to run slower or not at all so that the bus can get warmed up quicker? There's a warning sign on the back that says something about not leaving it on (or off) or it might cause something to go amiss. Do you guys know anything about this?

[luvrbus]

That is a test switch  too to see if the fan will engage or disengage the clutch may be bad and locked in full fan mode,they default to the full mode if not working, if it is bad  set down before you ask prices 

[Glennman]

What would I expect to see if I turn the switch on and off?

[Glennman]

Here's a video with the best explanation I've heard yet on how a fan clutch should work and can be tested:

https://www.youtube.com/watch?v=8apahhMGCO4

[luvrbus]

Those fans have a air control solenoid inline wired from the ECM (normally closed) to control the speed  always check those if the fan just runs at 1 speed, when the engine is cold that fan is spinning so low you count the blades, the little control solenoid cost $185.00 made by Parker, one needs to keep the fan in good working conditions they rob you of HP and fuel economy   anywhere from 25 to 40 HP and a mile + per gal 

[Glennman]

Maybe this is a different subject for another thread, but the fan belt tensioners seem a bit cheesy as there's no way to lubricate them, at least what I can tell. They appear to be the weakest link.

[luvrbus]

Maybe this is a different subject for another thread, but the fan belt tensioners seem a bit cheesy as there's no way to lubricate them, at least what I can tell. They appear to be the weakest link.

They have sealed bearing some you can replace the bearing some  you can't but they are cheap  even on Amazon .most people carry spare idler pullies

[dtcerrato]

They have sealed bearing some you can replace the bearing some  you can't but they are cheap  even on Amazon .most people carry spare idler pullies

I'm no pro at this sheet but in some cases one can cross reference a sealed bearing number to a bearing requiring interval greasing but then you need to figure where the grease zerk will be. We have chose that option on a few old school bearings on our bus. Fwiw

[luvrbus]

I'm no pro at this sheet but in some cases one can cross reference a sealed bearing number to a bearing requiring interval greasing but then you need to figure where the grease zerk will be. We have chose that option on a few old school bearings on our bus. Fwiw

You can remove the dust covers on a sealed bearing and make any sealed bearing a oil or grease type bearing, he could buy a drilled grease bolt that holds it on if he wants grease, they try to keep grease away from the belts since most over grease

[dtcerrato]

You can remove the dust covers on a sealed bearing and make any sealed bearing a oil or grease type bearing, he could buy a drilled grease bolt that holds it on if he wants grease, they try to keep grease away from the belts since most over grease

10-4 I understand that. The way I explained it was not good, my bad. In various places on our bus I had the option to go from a greased bearing to a sealed bearing & didn't - I elected to stay with bearings that could be greased.

[luvrbus]

These new buses have sealed wheel bearings I don't if that is good or bad

[Glennman]

I'll be getting some of those spare tensioner pulleys for sure.

[epretot]

I'll be getting some of those spare tensioner pulleys for sure.

Is that what ultimately caused your fan to explode?

[Glennman]

The pulleys appear to be fine. I had a 10" long piece of 1/4" thick hex shaped steel jamb itself into the radiator. When it did, the fan blades all hit it breaking them and causing additional damage to the radiator.