From fire tanker to flatbed dump

[rdbrumfield]

I have this 1972 F700 with all the lights and sirens. Had it set up for dust control and haven't used it much. figured I might as well pull the tank off and make a nice flatbed with hoist.
Wow, started buying steel, hoist and such, couldn't believe how much it has gone up.
Anyway, pulled the tank off and built the subframe today. I put an air system on to run the water valves so I will keep the airtank on for low tires and such. I used a 1973 toyota celica airconditioner pump. they are two cylinder and have their own crankcase. Makes for a great compressor. On the tag it is tested to 425 lbs. Don't think 125 will hurt anything.
Have a couple of used propane tanks for the air and hyd. Will hang those later.
Tomorrow will cut some more gold and start fabbing the bed. Will take a few pics if anyone is interested.
By the way, this truck has 6071 original miles on it. Only drawback is the rearend. Rockwell with 6:83 gears. I have another one with 4:88's coming. Right now it runs about 40mph at 2500.

 

[jayste]

Sounds interesting. Looking forward to more and pics. I can relate to your phrase "cut some more gold"!

Jay

 

[RickB]

Depending on the transmission ratios, you may be just as well off with the 6.83 rear. Too tall a low gear is a PITA for off-road and heavy work.

 

[EddieWalker]

Sounds interesting. I have a 1983 F600 dump truck with a gas engine that gets the job done, but is also a constant project.

What brakes do you have? Mine has a vacuum booster under the cab, on the drivers side. It's a real pain, and I've replaced it twice. Now I'm messing around, hunting down hydraulic oil leaks. I'm pulling the rear tires off and going in there next.

One thing that I really hate, and see all the time, is the sissor lift system used to lift the dump bed. The hydraulic cylinder is run off the PTO, and that works great. The cylinder is attached to a T kind of shaped piece of metal that in turns is attached to several arms that lift the bed. It allows the cylinder to fit inbetween the frame rails, and gives more room for the bed. That T shaped thing has broke on my twice now. The first time I'm sure it was just fatigue since it's so old. The welder I paid to fix it didn't get it right, and the next time, I took it to the most expensive, but what I'm told, the best welding outfit in town. So far, so good.

When I look at dump trucks, and I do, I see that there are several other ways to lift a bed. Before commiting to any of the options available, I'd spend some time researching all of them. There is a difference in how bigger beds are lifted compared to smaller ones. I think it's significant and if I had it all over to to again, I'd buy a different truck just based on the brakes and the lift of the bed.

Like the other suggested, I'd wait on messing with the rear axle until everything else is done and you've done some test runs. If you want more speed, you can do it then, but depending on the load, the terrain and how far you are going, lower gears might be better.

Eddie

 

[Iplayfarmer]

...By the way, this truck has 6071 original miles on it...

I'll bet that truck spent at least as much time idling as it ever spent driving. It's still a pretty low use truck, though.

If it came from a fire department anything like the one I volunteer with, you know that it had all the required maintenance on or ahead of schedule. It will be a great truck for you.

So, are you going to keep the lights and sirens when it's a dump truck?

 

[rdbrumfield]

I would love to keep the siren and lights, but you know that big red light is right in the middle of the roof and I need a place to mount a spare tire, and it would help protect the cab.
Today I put the new pump in, fitted the hoist and welded it up to the main and subframe and put the rear of the bed on.
Tomorrow, it is cut all the crossmembers, stake pockets, headache rack, mount the air and hyd tanks. Big order, will see how far I get.
It is turning out to be a bit higher than I would like, but that hoist mechanism needs some room to fold up and the truck frame has a crossmember right under it with just a couple of inches to spare. Other than that things are coming together nicely.
First order tomorrow is take a pic.

 

[Iplayfarmer]

...First order tomorrow is take a pic.

Definately!! Pics are a must.

 

[mjncad]

I second the call for pics!

 

[J_J]

Sounds interesting. Looking forward to more and pics. I can relate to your phrase "cut some more gold"!

Jay

I am sure the [ cut some more gold ], refers to the price of steel. The price of junk metal has dropped. but the new steel suppliers are keeping the prices as high as possible.

 

[Lloyd_E]

Would like step-by-step pics. I have a buddy who will be doing this soon...

TIA

Lloyd

 

[rdbrumfield]

Spent some time on the project today and took a few pics. Had a problem with the welder and had to change out the wire sheath, was sticking and giving me the fits lol. Also with all the wet here, welding is one of those delightful things to do if you like getting shocked while laying a bead down. Maybe that's why some of them look like I have a bad case of shakes after new years.
These pics are of the way I bolted down the subframe to the truck, the system for operating the hoist. I didn't want to make a long slot in the floor so I went with a rod sticking up that I can twist, works great with little pressure. The one of the rear pivot is not by the book. They call for cutting out the truck frame and mounting it there. If I had done that I would not have had the room for the hoist mechanism between the bed and truck frame. Besides, no way am I going to cut or drill holes in that truck.
I see I need to do some deslagging from the stick welds on that hinge.
These are a few I took today, if there are any questions on how or why I can get into detail.

 

[rdbrumfield]

cross pieces, will have the stake pockets in tomorrow hopefully. They help tie in the side rails. I have done it this way on several trailer and flatbeds. works well.

 

[mjncad]

Looks good and it appears that it's going to be a tight squeeze getting out the door. Keep the pics coming please!

 

[rdbrumfield]

Well folks, the bed goes up and down lol. Got the plumbing done today, works great, and is fairly fast to get up there.
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Finished the cabguard framing and hung the clearance light steel. Won't put the lights on until the paint is dry.
Tomorrow I will put the steel deck on and do the cabguard plate and expanded metal, hopefully if I get that far. Then some cleanup with the grinder and paint. Oh yes, a two step ladder and a handhold on the cabguard, a place to put a shovel and broom. that should just about do it. Almost forgot, sideboards and a tailgate. Does it ever end lol.

NO, then there is the trailer hitch. I have a pintle-ball combo to use and wiring for that. Looks like another week. Oh well, it is raining outside anyway.

 

[ben2go]

Good build.That's a nice rig you found.

 

[Iplayfarmer]

Now what are you going to do with the tank?

 

[rdbrumfield]

Any ideas farmer? I will take the lights for backup lights, but the rest will most likely go to the scrap yard.
It does have a nice 12v powered hose reel, wish I had a need for it. Thing is if I kept everything, well you know how it can get I suppose.

 

[jayste]

Can you convert the 12V hose reel mechanism into a way to run the auto-tarper if your local DOT insists on having one?...tarp that is. Just a thought. Nice job on the dump bed.

Jay

 

[Renze]

Do you intend to leave those strips of plywood between the truck frame and the dumpbed subframe, or are those to not scratch too much on the truck ?

From my time at a truck bodybuilder, i noticed in bodybuilders guidelines of several truck manufacturers that putting wood between the truck and the subframe was strongly disadvised, however this was common practice in the old days.

I see you mount the bed with long threaded rods: these will allow enough movement and stretch, to prevent your truck frame from cracking.
Another thing advised by Mercedes was cutting a V shaped notch in the horizontal flange of the subframe C-channel: This allowed the tip to bend, to prevent that the rigid end of the subframe channel would cause peak stresses at that point in the truck frame.

 

[Iplayfarmer]

Any ideas farmer? I will take the lights for backup lights, but the rest will most likely go to the scrap yard.
It does have a nice 12v powered hose reel, wish I had a need for it. Thing is if I kept everything, well you know how it can get I suppose.

Yes, I know how it can get.

There are a lot of guys here in the high deserts of Idaho that use old tanker beds for cattle water trucks. You could probably get some money out of it if you listed it on Craig's list or in the want ads.

Does it have a pump on it too?