FLU419 SEE HMMH HME Owners group

MajorMogger

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Well, I had already ordered a bunch of bulbs because I figured if brights worked on one side and not the other and vice versa it must be the bulbs. I was wrong and now have a lot of spare bulbs.

I had already wiggled the fuses the week before but they needed re-wiggling. Now ALL my lights work except brake lights -brights, low, front/rear signals, auxiliary lights, work lights, dash lights etc. New fuses will be here Wednesday and I'll go through and replace them all.

Questions:

1. I have a fuse labeled KBI (there is a paper label in the fuse boxes that don't seem to correspond to the diagram.)

2. I only tested the brakes w/ the engine off so maybe that needs air pressure before that will work?
 

MajorMogger

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What is the preferred pintle hitch trailer for the FLU419? Is there one that is at the right height in particular? Anyone pulled a water buffalo behind one?
 

Speedwoble

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New Holland, PA
Well, I had already ordered a bunch of bulbs because I figured if brights worked on one side and not the other and vice versa it must be the bulbs. I was wrong and now have a lot of spare bulbs.

I had already wiggled the fuses the week before but they needed re-wiggling. Now ALL my lights work except brake lights -brights, low, front/rear signals, auxiliary lights, work lights, dash lights etc. New fuses will be here Wednesday and I'll go through and replace them all.

Questions:

1. I have a fuse labeled KBI (there is a paper label in the fuse boxes that don't seem to correspond to the diagram.)

2. I only tested the brakes w/ the engine off so maybe that needs air pressure before that will work?
The brakes do not require air to function, though they require air to function well. The brake lights should illuminate when pedal is pushed.
Assuming you are familiar with proper operation of the military light switch, try the black-out lights to see if their brake lights work.
or just pull the covers off and check whether you have LED retrofits.
 

The FLU farm

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What is the preferred pintle hitch trailer for the FLU419? Is there one that is at the right height in particular? Anyone pulled a water buffalo behind one?
I can't remember if I've ever pulled the water buffalo behind a FLU, or any of the other ex-military trailers.
But I have used them for moving Class 8 trailers, with a con gear. And also for flat towing a Jeep and a John Deere Gator.

Anyway, I've converted most of my bumper pull trailers to lunette eye, so in theory I could pull them with a FLU. Would most likely require welding on a longer (taller) channel, though, to get the height correct.
 

glcaines

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What is the preferred pintle hitch trailer for the FLU419? Is there one that is at the right height in particular? Anyone pulled a water buffalo behind one?
I've pulled my M149A2 water buffalo trailer behind my FLU419 on several occasions, offroad and Very Slow. The FLU has minimal power when the tank is full and the trailer tends to push the FLU. Not recommended.
 

Mullaney

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Hmm. Sounds like you wouldn't approve of pulling one with an M1008 then, which is what I normally use.
And it's been shorted by 31 inches and has no bed, so not quite at 16,000 lbs. like a FLU.
.
Yes Sir - or maybe - No Sir!

The Army Reserve units that deliver water buffalo's to Scouting district events were always delivered with a Deuce. A standard Buffalo M-149 is 400 gallons coming up to about 3200 pounds of water plus trailer and will definitely push around anything smaller.

Guess I'm "chicken" but yeah, not anything small - and especially not if it isn't full to the top!
 

MajorMogger

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Texas
For about ten years I hauled a 425 gallon plastic tank in the back of my 1986 6.9L IH IDI F250 and had no issues with it. I'm surprised the FLU419 would have troubl w/ the water buffalo? I suppose the trailer is a lot of extra weight but I figured I had about 3800 pounds of water in the back of that F250. Granted never went over neighborhood speeds because I didn't have to. But we do have hills and stuff here and no issues.

My community has frequent water outages and I'm trying to come up with a way to move water between functioning water wells to people who are on the central rural system that gives out frequently. Also wouldn't hurt if I could double it as a firefighting trailer at some point.

It might make sense to just get a trailer and put a plastic tank in it instead, the water buffalos seem to have gone way up in price.


I don't see how the FLU419 could have trouble w/the water buffalo if it is rated to pull 17,000 lbs?
 
Last edited:

glcaines

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As I mentioned above, I have pulled my water buffalo with my FLU419 several times. As Mullaney mentioned, it is MUCH safer to pull the water buffalo with the tank full, or if not, empty. A partially filled 400-gal tank with water sloshing around really gets squirrely, especially on uneven ground. Although I've pulled my water buffalo with my FLU419, I normally pull it with my M35A3 deuce. No problem pulling it with a deuce. I think some of the issues with pulling the water buffalo with the FLU419 come from the short wheelbase.
 

rtrask

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How are you all?
I have had a busy year or so, and have not had much time to do much other than keep putting on foot in front of the other. In the last year I have dealt with years of differed maintenance on our former home, and sold it. Bought two 40' high cube shipping containers and moved 20+ years of accumulated "stuff" 170 miles south and filled them up to over flowing, in addition to filling two large dumpsters, and made countless trips to Good Will. We bought a 40' 5th wheel and moved into it.

Since then we have selected a modular home, and have been working through the bureaucracy to get an address (you would not believe how hard that is).

To get back on topic: How important are the fans on the hydraulic radiator? Do they only kick on when the fluid gets "hot" or should they always be running? Mine have never kicked on, and are likely in need of some TLC. I have not run the backhoe for more than 3 or 4 hours at a time, and the ambient air temp has been in 30's to low 40's. I will frequently grab the supply line to see how warm it is and it has never been hot. I have thought about putting a thermometer to get an idea of how hot is running at, but it is comfortable to hold on too. I have read that it should be kept under 180 Fahrenheit, it is no where near that.

I have a lot of earth to move, but a lot of time to get it done. I need to replace the seals on the dipper cylinder, I replaced the ones on the boom cylinders, and the bucket cylinder. If I need to replace the fans too, I will order some. Maybe it is just wiring, but I have a lot to learn about it's proper operation.
 

Mullaney

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How are you all?
I have had a busy year or so, and have not had much time to do much other than keep putting on foot in front of the other. In the last year I have dealt with years of differed maintenance on our former home, and sold it. Bought two 40' high cube shipping containers and moved 20+ years of accumulated "stuff" 170 miles south and filled them up to over flowing, in addition to filling two large dumpsters, and made countless trips to Good Will. We bought a 40' 5th wheel and moved into it.

Since then we have selected a modular home, and have been working through the bureaucracy to get an address (you would not believe how hard that is).

To get back on topic: How important are the fans on the hydraulic radiator? Do they only kick on when the fluid gets "hot" or should they always be running? Mine have never kicked on, and are likely in need of some TLC. I have not run the backhoe for more than 3 or 4 hours at a time, and the ambient air temp has been in 30's to low 40's. I will frequently grab the supply line to see how warm it is and it has never been hot. I have thought about putting a thermometer to get an idea of how hot is running at, but it is comfortable to hold on too. I have read that it should be kept under 180 Fahrenheit, it is no where near that.

I have a lot of earth to move, but a lot of time to get it done. I need to replace the seals on the dipper cylinder, I replaced the ones on the boom cylinders, and the bucket cylinder. If I need to replace the fans too, I will order some. Maybe it is just wiring, but I have a lot to learn about it's proper operation.
.
Trucks and Track Hoes and other things with a Hydraulic Radiator and fan may not cause the fan to turn on. Especially in the colder weather. You won't be able to miss it the first time the fans turn on! It will sound like the vehicle is going to explode... (or it sounded that way to me the first time I heard it.)

You could get one of those point and shoot thermometers at Lowes or Home Depot or Tractor Supply or Ace Hardware. Cheap way to be sure the temperature is what you think it is...

Then get yourself a piece of cardboard the size of the radiator and block the air flow on the non-fan side. Yeah, I know the fan isn't running but the cardboard will keep the heat you have and possibly generate more.

You might check the fuses to make sure that the fans can turn on. Somewhere there will be a temp sensor and that may need to be looked at - but blocking the radiator is the cheap easy first test.
 

peakbagger

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If you run the backhoe as intended in warm weather the fans should cycle on and off. I did an extended project and an 85 degree day and they were running full time. Some folks like FLU farm runs the backhoe at low engine speed and I expect that the fans really do not have to run.


There is a technical service bulletin that confirms that many of the FLUs were assembled with the wires to the fan entering from the top of the of the fan motor housings. The rubber grommets fail allowing water to fill up the motor housing and short the motors out. Someone mentioned that the fans can still be bought directly from Hayden. I just found similar sized Spal fans on Ebay and made up and adaptor plate.
 

Sgt Jiggins

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When first starting out I had the same questions about the fan assembly on the back (among plenty of other questions). I think the first time it turned on for me it was around 50F ambient. But I wasn't all that surprised, mainly because I had an idea of what to expect.

They are loud. I learned this while manually engaging them. There is a little terminal block with 3 lugs that if memory serves is on the inboard side of the fan. That is where you can (temporarily) jumper the individual fans. Or at least that's where I did it.

Use your battery disconnect (never! engage it while the truck is running!!). Be safe. Get a soldier B.

Good luck!
SJ/JD
 

The FLU farm

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It wasn't long ago that I looked at the fans and thought "If one dies, I'll just leave it dead. If both die, so what?"

As peakbagger mentioned, I keep the engine at fairly low rpms for the very most part, and combined with ambient temps that are almost always below 80 degrees, the fans have rarely come on.
And like rtrask, I feel the lines every now and then, just in case. They've never felt even close to hot, just warm.

Now, when running the snow blower the fans were on a lot, but that meant that the hydraulics were running full bore, and the engine at 2,000 rpm or better.
On the other hand, the MB 4/94 tunnelwasher had a larger hydrualic tank (38 gallons if memory serves me), but no fans.
 

Mullaney

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It wasn't long ago that I looked at the fans and thought "If one dies, I'll just leave it dead. If both die, so what?"

As peakbagger mentioned, I keep the engine at fairly low rpms for the very most part, and combined with ambient temps that are almost always below 80 degrees, the fans have rarely come on.
And like rtrask, I feel the lines every now and then, just in case. They've never felt even close to hot, just warm.

Now, when running the snow blower the fans were on a lot, but that meant that the hydraulics were running full bore, and the engine at 2,000 rpm or better.
On the other hand, the MB 4/94 tunnelwasher had a larger hydrualic tank (38 gallons if memory serves me), but no fans.
.
Pretty amazing how about 3x the amount of hydraulic fluid in a thin sheetmetal tank keeps the fluid temp down. My M-936 has no fans, engine runs at 1500rpm and a hundred gallons of hydraulic oil. It will run all day and not be much warmer than the air surrounding it.
 

rtrask

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When first starting out I had the same questions about the fan assembly on the back (among plenty of other questions). I think the first time it turned on for me it was around 50F ambient. But I wasn't all that surprised, mainly because I had an idea of what to expect.

They are loud. I learned this while manually engaging them. There is a little terminal block with 3 lugs that if memory serves is on the inboard side of the fan. That is where you can (temporarily) jumper the individual fans. Or at least that's where I did it.

Use your battery disconnect (never! engage it while the truck is running!!). Be safe. Get a soldier B.

Good luck!
SJ/JD
Last night after I posted, I did what I should have done to start with, and followed the adage RTMS "Read The Manual Stupid". In the manual on diagnosing those fans it says
Code:
74. HYDRAULIC OIL COOLER FANS WILL NOT OPERATE.
NOTE
Vehicle MASTER disconnect switch must be ON and ignition switch
Failure to do so will cause erroneous results.
Refer to wiring diagram (page 3-256) for all wiring repair steps.
So it sounds like the fans will never run, if you don't have the master disconnect switch engaged. I am also non standard because I put an electric fuel pump in line before the pre-filter screen. That requires the master disconnect, and the ignition switch to be in the on position to run. The inline pump is probably not strictly needed, but I it is kind of a belt with suspenders warm and fuzzy. I could probably run with out it. But.....

This is the first I have heard that you should never run with the master disconnect engaged. Can you explain why it is bad to do so?
 

rtrask

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Thanks all for your replies. I guess now that the fans may actually be OK, but my spider sense tells me not likely. I have a power probe II and I will hook it up to the battery and try to apply 24 volts to it to see if they kick on. Does anyone know what temperature they are supposed to kick on at?

Among the other things that I have not yet bothered to make work are the two switches to bump up the RPMs and to raise and lower the front bucket. It is less than ideal, but I just leave the front bucket up a couple of inches and use the manual throttle to set the RPMs. It is on my "to do" list to fix that,, but it is a long list and it may be a while. Have any of you all got those switches working properly, and how hard / expensive was it?
 
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