Engine fan: Mec or elec???

Joe45 · 10-08-2019, 01:00 PM

So the fan clutch on mt T444e is shot. I can spin it like its totally loose. Almost zero resistance.

Trying to decide whether to install a new clutch (AAA Bus is sending me one for free), or to switch to an electrical system.

I've hear some people say electric ones don't have the power for this application, but don't other diesel truck with similar engine use electric fans?

Anyone put on an electric fan system? I see them online but the prices range from $45 to $400 and up.

Thanks!

Johnny Mullet · 10-08-2019, 01:24 PM

Regardless the old fan clutch has to be replaced. Eventually it will come apart.

Joe45 · 10-08-2019, 01:41 PM

Quote:

Originally Posted by Johnny Mullet

Regardless the old fan clutch has to be replaced. Eventually it will come apart.

Yeah, I'm struggling with how to get it off right now.

Just need to determine whether to put in a new fan clutch, or go electric.

Johnny Mullet · 10-08-2019, 02:41 PM

I remove them with an air chisel.

Booyah45828 · 10-08-2019, 03:45 PM

Use a new clutch. If you're worried about fuel economy, get an electric clutch.

Going to completely electric is asking for issues. You'll have to have some serious fans to pull enough cfm through the radiator to cool. So much, that I truthfully don't think it's possible/pragmatic.

And, at the end of the day, is it worth overheating and possibly ruining your engine by trying something like this? The mechanical clutch is a pretty reliable system, I'd keep it that way for peace of mind.

Brad_SwiftFur · 10-08-2019, 07:06 PM

I'd not bother with an electric fan system for a bus. You *NEED* way more airflow than most electric fans can produce. Hard working diesel engines produce a *LOT* of heat and electric fans simply don't have the same air moving capacity as the mechanical (belt driven) ones do.

No, big trucks and buses do not use electric fans. Some rear-engine ones have hydraulic fans.

Now as for your fan clutch, there is the typical hydraulic clutch (probably what you have now, as do I), air and electric clutches (the air clutch is fairly common in big trucks). Personally, I'd not bother changing from what the factory used since they are pretty reliable and long lasting.

Joe45 · 10-08-2019, 07:34 PM

OK
So the regular belt driven fan it is!

Sleddgracer · 10-08-2019, 07:35 PM

fans with a clutch spin freely when the vehicle motor is cool - it's supposed to be free spinning - before you junk your fan, let the motor warm up enough that the fan kicks in - if it kicks in when the motor is hot, then there is likely nothing wrong with it

Joe45 · 10-08-2019, 07:35 PM

PS

Anybody know if this fan clutch unscrews clockwise or counterclockwise?

Joe45 · 10-08-2019, 07:38 PM

Quote:

Originally Posted by Sleddgracer

fans with a clutch spin freely when the vehicle motor is cool - it's supposed to be free spinning - before you junk your fan, let the motor warm up enough that the fan kicks in - if it kicks in when the motor is hot, then there is likely nothing wrong with it

I drove the bus into the maintenance bay at the school district where I work. The mechanic moved the fan around and said it was shot. It was about a 15 mile drive to the school.

Johnny Mullet · 10-08-2019, 08:09 PM

Quote:

Originally Posted by Joe45

PS

Anybody know if this fan clutch unscrews clockwise or counterclockwise?

Lefty loosey on that engine

Joe45 · 10-08-2019, 09:10 PM

Quote:

Originally Posted by Johnny Mullet

Lefty loosey on that engine

Thank you kindly!

WARGEAR · 10-10-2019, 02:47 PM

Transit buses use electric fans for the A/C systems!

Joe45 · 10-14-2019, 10:57 AM

Yeah but cooling the A/C is a lot different than cooling the engine.

I have thought of using the old A/C condenser fans as additional cooling fans for the engine.

Have also thought of relocating that heater core from inside to outside to serve as a mini extra radiator.

cadillackid · 10-14-2019, 11:58 AM

UGH! dont use an air chisel! thats hard o nthe water pump.. the 444E uses a 2 inch wrench and you use a spanner that holds the water pump stopped..

oleman · 10-19-2019, 03:42 PM

Quote:

Originally Posted by WARGEAR

Transit buses use electric fans for the A/C systems!

Yes, but ours (GILLIG) has a 300A 24 V alternator to carry the 100A idle load on the 2 group 8 batteries in series. Engine fan runs off a hydraulic motor driven by a pump that also runs the power steering.
Transit buses are special critters!! They normally heat and cool over 50 passengers 7 days per week for 500,000 miles in their lifetime.

rv8flyboy · 10-21-2019, 11:21 AM

One thing not mentioned here, unless i missed it.

Check the temps of the hoses to the radiator with a thermometer. I believe they should be within 10 or 15 degrees, anything more and u may have a clogged radiator.

I went through the gyrations of replacing the fan clutch only to find out the new clutch did the same. And after the engine got hot you could stop the fan quite easily with a rolled news paper and spin it backwards by hand.

Das where i learned to measure hose temps. If the radiator is clogged or the thermostat is hosed, you wont get enough heat from the radiator to get the viscous clutch going. On the surface it will appear as a bad clutch.

Joe45 · 10-22-2019, 03:36 PM

Quote:

Originally Posted by rv8flyboy

One thing not mentioned here, unless i missed it.

Check the temps of the hoses to the radiator with a thermometer. I believe they should be within 10 or 15 degrees, anything more and u may have a clogged radiator.

I went through the gyrations of replacing the fan clutch only to find out the new clutch did the same. And after the engine got hot you could stop the fan quite easily with a rolled news paper and spin it backwards by hand.

Das where i learned to measure hose temps. If the radiator is clogged or the thermostat is hosed, you wont get enough heat from the radiator to get the viscous clutch going. On the surface it will appear as a bad clutch.

That's a good point!
I tried getting the fan clutch off using a tool rented from Oreilly's, but wasn't able to. None of the pieces fit the fan clutch nut! I returned the tool and went back to working on the bus because I am frankly sick and tired of doing mechanical work from years of struggling. Would rather use my energy to get the interior done. I love being creative, and doing the cabinets etc. is fun, but mechanical stuff on the engine I simply can't stand anymore!

I'm gonna have a local mechanic who is an International Guru do it for me. Under $50. I'm gonna have him check the hoses etc.

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