1988 GMC C7D (C7000) Lots of Questions

Hi,

I know that this particular group may be for true blue OTR Tractor mechanics, and if my questions here seem like a waste of time? My apologies.

If not, this is my situation. I came over here from Yesterday's Tractors (as in farm tractors) where I've been a forum member for years. Our farm as a few older agricultural tractors and a bunch of old tilling/harvesting implements that I've put into, and keep in, running condition, sometimes from the scrap heap.

My experience level is... "Motivated Guy with an Engineering Degree that grew up on a farm..."

Anyway, we recently bought a 1988 GMC C7D (according to its title). It was originally a dump truck. The PTO remains on the transfer case, and the hydraulic spooler/fluid tank is still mounted to the chassis. The piston and pump are gone.


I'm a firm proponent of knowing what I don't know... and learning that. What I'm here for is.... to learn what I don't know that I don't know. Experienced people can point out things that I didn't even consider.

What I know:
It smokes when you start it cold. (I looked at it at 22 deg F and started it with no fluid, block heater or glow plugs).
It stops smoking after about 15 minutes
When you run it on the snow, you can see a "soot spot" under the exhaust
If you warm it up and shut it off... then restart... it's a super fast restart and less smoke.
It has sat around a lot over the last few years, at least.
It has a six digit odometer that reads 59,000 miles
It has a Detroit 8.2L diesel
That particular motor doesn't have a good reputation...
But... if you load that motor lightly and follow certain rules regarding oil and coolant, it CAN (can being the operative term) last., according to what I've read... this is my first experience with a Detroit.
It has air brakes that work. I mean, the person that I bought it from put his dealer plates on it and drove it twenty miles on NYS Routes 8 and 12.
I haven't performed the official "leakdown" test on the brakes... but my gut feel is that the air doesn't recover fast enough to pass inspection

What I'm trying so far:
I added some Sea Foam and Power Services Additives to the Tank. Ran the engine for about twenty minutes... rocked the truck back and forth hard a few times with the clutch and brake (to slosh the fuel)... and drained the tank.

I'm going to remove the tank and take care of any surface rust, especially where the mounting straps chafe on it... and while it's out, I'm going to replace the sending unit (fuel gauge doesn't work)... and replace the fuel filter and fuel lines right above/behind the tank. The existing fuel filter right there looks dented and rusty... and the lines look sketchy.

I need to get the fuel tank back on it with all of that stuff taken care of to run it again, in order to leakdown test the air brakes and such.

I also wonder how much of the smoking problem was just crappy fuel and an engine needing to be "desooted" by being run up to temperature and kept there for a while, with clean fuel going through.

What I'm having trouble with.

Brake parts. How do I identify brake parts for this? I took my make/model info to the counter guy at NAPA, and their lookup system identified disc brakes. Truck has drums.

Do I get the make/model of the rear axle? Will that help me? I remember seeing a recognizable name on the rear axle (I want to say "Dana")... but the name escapes me at the moment. I didn't write it down.

Also... there are visible cracks in the rear brake shoes (I haven't taken the drums off yet). There is A LOT of shoe left, but maybe they get brittle with age? I'm thinking that shoes is a small, small investment for peace of mind at this point; and it will give me an excuse to pull the drums and check everything else in there.

Also... the drums... I've pulled the monster drums off of an old Ford 2N agricultural tractor without much problem. I've also torched and beaten my brains out on a tiny set of rear drums on a passenger car. Should I expect WWIII to get the drums off of this thing? Is there any trick of the trade here? Or is it just... heat and pound, as you do with any drum?

There's going to be more. Here are a couple of pictures, as a reward for reading so far.

Thanks in advance

 

Well... I mean... I DO remember growing up on the farm. In the winter, my brother would go out back to the shed where the big old International 856 sat, hooked to the manure spreader. He would start it up and let it run while the barn cleaner ran. In those fifteen minutes or so, the whole barn (which was a 120 cow dairy... so pretty big building) would fog up with diesel smoke. My uncle did the same.

After I grew up, I rented a house at my uncles farm. He always said that the block heater was expensive to run. He would go out there on cold days... let the tractor spit and sputter as it tried to start... give it ether... have it sputter to life... and then breathe in diesel fumes as he cleaned the barn. The whole barn would have a blue fog in it, even if he closed the door between the barn and the manure shed, where the tractor was warming up.

On the weekends, I would sometimes do chores for him. I would walk out to the barn before breakfast and plug the tractor's block heater in. Go back inside. Eat breakfast... go back out and do chores for an hour or so... after the barn was clean, I would start up the tractor... with a fraction of the smoke...

Maybe I just need to apply what I learned back then, and, if I keep this truck for the long haul, just park it where I can plug in the block heater before I use it on cold days.

I've also read that these engines really like to have a pre-oiler installed, especially if they have to sit a while between uses. Maybe I'm thinking a little too fancy there.

I know it's just an old truck... but I bought it for the equivalent of the sales tax on a new, pretty truck that won't carry what this thing can. Even if I baby the engine. The working weight and braking make this a much safer way of moving hay and wagons than a nice, new, pretty pick up truck. Oddly, the replacement cost makes this an investment that I want to protect.