Hi,
I recently came to own several pieces of Cat and Wabco equipment, including three 8T 12 graders (one parted out), two 3T D7s (one parted out) and two Wabco cable scrapers. One grader and the D7 ran when parked, but have sat for around 10 years. You can see in the attached photos that the paint is far from original. The D7 pony was locked up using ether (likely the crank or connecting rod...), so it now is pull start only. Due to this, my first effort is focused on getting a grader running...

8T1936 Grader
I can turn the pony and the diesel over by hand, but the pony has no spark and significant rust in the gas tank. Can anyone offer ideas to diagnose the no spark condition? I already tried to disconnect the kill switch (since it looked like a simple grounding switch). I also pulled the distributor/mag cap and everything was dry and very clean like new. What are the chances of the carb working if I get clean gas to it via an external tank? Or, do I need to start off by pulling the carb to clean and rebuild it?

3T8653 D7
Can someone please tell me the year this was built? My grandfather and great grandfather worked at Cat East Peoria as tool and die makers. I am curious if this tractor was built during their tenure. The diesel is stuck and I am unable to turn it with a 1.5' bar on the crankshaft. The main clutch feels like it will engage and release, but is very tight. As you can see in the photo, the exhaust has a cap over it. Any advice on where to start? I assume I need to pull the injectors and dump WD-40 or similar in the cylinders.

Thanks in advance for any advice.

hello mccsl,the d7 3t8653 was built in 1948 ,

like the colour of the d7

the grader 8t1936 was built in 1948 also and has the d318 motor the same as the d6.
the kill switch is like you say ,only a grounding switch.
it could be the points or the condenser not working ,others will have better info ,
i wouldn't use the pony tank until it is cleaned ,and clean fuel line if it has been sitting for so long ,carbie may need cleaning out to ,may have rust in it to .have fun getting it going and post more pic ,bruce oz

Good advice on cleaning the tank out and cleaning the carb too. Try just cleaning the points on the mag and see if you get some spark. Hang in there and you'l get her going. Also I have all the books for that grader. Let me know if you are interested. Charlie

Where did the grader come from? It looks like one of the ones we owned back in Phila PA.All three of them were sold about 3-4 years ago aT AUCTION.

Before you start the pony motor off your clean gas supply, make sure the governor arm is free to move. It should snap the throttle wide open when you push the throttle control in. The control pulls the throttle/governor arm to slow the engine and/or limit the governor in responding to a load.

If you can't get gasoline through it, most of the worst clogs can be resolved by removing the top of the bowl which gets the float, needle and seat and high speed mix needle off and gives access to the main and compensator jets in the bottom of the bowl. There are also two plugs in the bowl, one is a drain and the other on the corner exposes the high speed metering well which is removable. A good cleaning will usually at least get it where it will run with the choke on all the time.

Initial adjustment is one turn open on the high speed mixture adjustment screw in the top of the bowl and a half turn open on the idle mixture screw over on the opposite side of the carburetor venturi from the bowl. The high speed screw is adjusted out to richen the mixture, but the idle speed screw is adjusted IN richen the mix.

Another thing to watch out for is if you remove the bowl from the side of the carburetor body, the gasket should have two rings of material, sort of a bulls eye. Sometimes the center ring is gone and it won't run very well or at all that way.

Depending on how the diesel governor throttle was left, the rack may be stuck open or closed. It might be prudent to remove the cover on the side of the injection pump and watch the rack move back and forth as you move the throttle control BEFORE you start it up. If it's stuck it's usually a pump plunger that's holding it, so spray them and work any stuck ones up and down so they loosen up and twist freely in the pump and the rack will usually free up. The injection pump housing has it's own oil supply so you can check it while you're right there.

Sounds like a good plan on the 7. That might just do it.

I would also spend some time draining any accumulated water from the bottom of all the gear cases, and fuel tanks, filter housings and crankcase(s) of the engines before you disturb things and mix the water with the fuel/lube on top. It only takes loosening the plugs and see what seeps out to find and get rid of a lot of gunk and avoid mixing it all in. If you need to bleed the fuel system after draining the filter housing etc, use a section of inner tube with a valve stem on it, clamped onto the fuel tank filler to pressurize the tank and force fuel through the system all the way to the injectors.

Magneto points should be gapped 0.014" to 0.018". Like Charlie says, after 10 years they usually have a layer of corrosion on them that must be filed off to get them to conduct. Be careful putting the cap back on the magneto, the brushes are sort of delicate and you don't want to have to stop and look up some of those before cranking it up.