Received 2002 M1097A2 for firetruck build - looking for advice

[Retiredwarhorses]

Soooo, you have an overheating motor and not a single mention of performing a cooling system test?
Basics man, basics….you need a pressure system tester, the motor should be able to run for quite a bit before it gets to 220, its
almost impossible to get the truck to temperature while just sitting and idling, if it’s headed to 240 at idle?
you have at minimum, a stuck closed tstat…but i fear it may be worse than that Based on my experience

 

[NotThatGuy]

Anything we should do to improve?
How well will it do fully loaded or should we make sure we don't?

I downloaded the manuals already. But I am new to military vehicles. I usually work on gensets and manlifts and other equipment, but it looks like I will be the main mechanic on our little fire dept. We are supposed to turn this into a fire fighter within 180 days. It runs fine according to someone else who drove it - he said the temp guage showed hot when powered up - so I guess that is the first thing on the list.

There's a very well put together engine cooling troubleshooting flowchart in the TMs.

Problem is that most people don't have the correct diagnostic tools to complete the tests, (i.e. a radiator cap pressure tester etc).
Just Sayin

 

[NotThatGuy]

Soooo, you have an overheating motor and not a single mention of performing a cooling system test?

+1

 

[draymorris]

+1

I know we don't know anything about one another, it is something that makes discussion forums difficult sometimes. So, don't take offense to what I say.

When the cooling system is full and stays full and is parked on concrete for days and no drips of anykind, then I typically don't look for a leak in the cooling system, because it is not loosing any coolant. Again, no offense to anyone. But I check the system - held 15PSI for over 4 hours - good enough for me.

As for the "stack"- I simply shined a bright flashlight into the bottom side and moved my head around looking for light through the stack - no problems there .

I have crawled around under this unit and there is no sign that this thing was every driven in anything that would even take the paint off. So I was not to worried about debris being between the cooler and radiator.

So these are the reasons I did not mention the basics to start with - sorry.

Followed the test procedures for the gauge and did all the stuff listed above in the post and the bottom line is that their test procedures are not complete as far as I am concerned - it said the guage was good - read nothing when disconnected and pegged when shorted - in between open and closed seems to be where the problem lies.

I installed a totally mechanical gauge and drove the heck out of it - engine heats up and cools down perfect as far as I can tell - fan kicks on at 200 and off at 190. Brought he sending unit in and got out the thermometer and meter - according the resistance chart above - it is within 100 ohms of working correctly. That could be just my meter or thermometer being off .

It seems that it is the meter itself, but at this point I think we are going to install the mechanical meter and put a led bulb in it that will work on 24 v for lighting.

The more I get familiar with this, the better it looks.

I truly thank you for all your help on the heating problem.

The build will move forward - it seems strong when driving it - shifts firm. The steering pump seems loud and might have a small leak. I will be changing all the fluids in everything when we get to going on the build. We just wanted to make sure we did not have lemon before continueing.

If any ideas come to anyone, send em. I think the tank and pump install will be pretty straight forward. I am putting thought into the lighting - I want to see if I can get lights or make lights or modify lights to go where they already are - but have all the warning lights in them and not have to run a lot of new wires. I have an old 18 wheeler that is hard to find turn and headlight assy. So when the turn signal lamp holders broke out of the plastic, I took 5 led button trailer markers, drill holes, heat stakes them in and now I have better turn signals - and saved about 550 per side on headlight assy.

Has anyone seen any of these with warning lights in the factory lights?

Thanks again.

 

[draymorris]

Update after all this time.
I got covid after Christmas and it really set me back for a long time. I thought long covid was hype, now I know otherwise. So the deadline after filing and extension for the grant was approaching, and I had to stop everything else in life to do the build. I wish I had never commited to it, but I made it. The rush caused me to do things that I don't like doing - substandard work is what I call it.

I will try to post pics as soon as I can but there are some things left to do. I got it to the point the grant would pay and stopped until I get reimbursed for everything I have into it, which at this point is 8500 dollars in materials, then the dept paid for the pump, hose reel and 2 nozzles. So at this point I think we are going to have 20k in it without any labor and it is not completely the way we want it.

I ended up building a 304 12ga Stainless steel tank that goes from the rear most mounting holes in the bed to the mounting hole between the front seats. So the tank is wider in the back and fits between the rear seat wells which will give a place to stand. I mounted the pump on a deck that I welded to the rear bumper, it is a 300psi Hale pump like we have on the duece and the 1 ton. The hose real mounts on top of the tank, it is electric, double sided fairlead so you can roll the 100 ft of lightweight 1" hose off either side and it reels it back up so fast you better be wearing gloves to guide it. Put 1 short whip hose for the guy on the back to use and if there are two the second guy can use the reel hose.

We are probably going to change our SOP when we get this going all the way - now, the first one at the station is supposed to wait for another person before heading out in the 1 ton - it is hard to drive and spray to you always need 2. We plan on making this the 2nd out the door if we know a 3rd is coming to get the big tanker. That means we can get 2 nimble 300 gallon trucks there to start the initial fight and if this Humvee is there we can empty 1 truck as a 2 person crew and then jump in the Humvee and go back to the fight, while the tanker is heading to the scene. It should be pretty effective because after people start showing up we will have everything on scene and should have enough people to man everything. The duece is so slow and hard to drive, it is the least of the units - it could get you in trouble in brush because it is so difficult to drive. I would have hated to be running from the Germans in WW2 and relying on one of those to get me out.

All we could find for plastic skid units was minimum 20k so we did what we did. I spoke to the company that I ordered the hose from and they said there minimum skid mounted unit that would not have fit right would be 28K. So I think we did the right thing, it just stressed me out getting it done on time.

I took it to town to get a loaded and emtpy weight last week and it is 9300 with no bodies in it. I weight close to 300 and my favorite partner is about 400 so we will load it down when we get it in service. I still have to build hand rails and such, mount lights and radio. The requirement for the grant was that it has to be "not original paint" and spray water like a fire truck with a real fire pump and built to operate correctly. Coming back from town one of the 22 year old tires blew a hole in the side wall - I was pulling back into the house so it was no problem. So it is time to order tires.

I also have 3/16th aluminum to build the top and a back wall with, but have not started that. My plan is to roll the edges on the top and cut it to make a visor over the front window to mount emergency lights to the visor part. I am planning on mounting it over the soft top so the soft top will act as insulation. The doors - we are not sure yet. Probably going to try to make them out of aluminum also, but I need to find someway to get a window in them.

Driving it to town loaded was good. I was stable and the mechanical temp gauge I put on was staying at 190 and about 200, fan kicked on good. I was able to make the tank only 22 inches tall. If I would have made the tank from fender to fender in the back I probably could have done 20 inches to get our 300 gallons. But we wanted about 4 inches between the fenders and the tank to put a few tools and be able to get our hands in the gap. The substandard work is not really that noticable, and beside, this thing is not made for parades, it is made to go through brush.

I will try to post picks soon

 

[draymorris]

Also, the dual voltage alternator - I just tapped onto the first battery to run the wire to start the pump and wind the hose reel. Is there any reason why that wont' work long term and carry the load for the radio and a few led lights? How many amps can the 12volt output of the alternator handle?

 

[Coug]

Also, the dual voltage alternator - I just tapped onto the first battery to run the wire to start the pump and wind the hose reel. Is there any reason why that wont' work long term and carry the load for the radio and a few led lights? How many amps can the 12volt output of the alternator handle?

First battery is usually defined as the one connected to the positive lead of the truck. It's the second or rear battery to tap into for 12V stuff.
The dual voltage alternator is rated for max 50 amps output for the 14V side of things. Of that you can plan on 10 amps reserved for the transmission controller, and you never want to max out an alternator, so you're only really good for about 20 amps of 12V continuous draw from the rear battery.
If you need more 12V power than that, the Victron Orion 24-12V 70 amp converter would be the way to go. If you need more than 70 amps, you can run up to 5 of them in parallel for up to 350 amps of 12V