model 12 grader

[jaker65]

hey all,
i was wondering if you could give me some help on this grader. if its worth it, i may, just may try and work a deal. im not sure if the motor even spins free.

http://pittsburgh.craigslist.org/for/1529990822.html

[Old Magnet]

That would be an 8T model....about 29,500+ units built between 1947 and 1957.
Doesn't look to bad but who knows what the running condition is. Don't run.....I'm thinking like $2,000 or less.

[jaker65]

Thanks OM, i was thinking the same. in the advertisement he says its not hydraulic, i was wondering if he was mistaken on this....

[Old Magnet]

Don't think he'd overlook something like that. I don't recall when they changed to hydraulics but the early ones were all mechanical. Might have a hydraulic steering booster upgrade which was pretty common. For 1950 your in the sr #
3725 - 6550 range.

[Deas Plant.]

Hi, Jaker65.
Take the man at his word. He said he is sick of looking at it so make him an offer.

The Cat grader line didn't go full hydraulic until the 'G' series was introduced in about the early-mid1970's. The Cat 14E, Cat 12F and Cat 112F all had hydraulic assisted controls in the mid-late 1960's. You can pick these by the fact that the blade lift shafts came BACK from gearboxes at the front instead of FORWARD from gearboxes in front of the cab. The control box in the cab was also a lot bulkier.

Take some GOOD batteries AND jumper leads/booster cables and about 5 - 10 gallons of clean diesel fuel and go have a look at it. Check the oil and water. In particular, look carefully at the oil(?) on the engine dipstick to see how high the level is as a possible clue to water in the oil pan. Study the color while you're at it.

Then check the rest of the machine to see if it worth going any further. A LOT of these old girls did accumulate a fair bit of wear in various places but there are also quite a few adjustments to counter that wear so it should not be a deal-breaker unless it is extreme. Broken or missing parts are another matter and you would need to consider repair costs.

There are a number of gear boxes in various places around the control shafts. Look for leaks around them and any oil on the ground under them, Unless there are cracks or breaks in the gearbox itself, any leak is most likely a worn or hardened seal.

Have a look in the fuel tank to see how much if any fuel is there. If the fuel is well down, you could remove the strainer - if it's still there - and dip a piece of rag in there on a wire to get a look at the quality of the fuel.

IF you then think it is worth going further, hook the batteries up and see if it turns without trying to start it. They say it had a pony motor on it orginally so there may well still be a decompressor lever there. If so, move the lever the opposite way from where you find it as it is unlikely that they would have opened the decompressors when they last shut it down.

When you first start turning the engine, keep an eye on the exhaust for any tell-tale signs, especially for any water if the exhaust has not been covered.

If it turns over, try to get it into gear while it is turning to see if the clutch disengages.

The gear pattern will most likely be one of two variants, depending on whether it has the high reverse gear or not. With no high reverse, it will be a standard 'H' pattern with first forward and reverse back on the side nearest your right leg. If it has the high reverse gear, that will be a 'round-the-corner' shift, even closer to your right leg from the low reverse.

The other gear lever is high and low range, if memory serves me right, high forward, low back. When changing up or down through the gears, you get to move the high-low range lever EVERY shift and the main box only on alternate shifts.

IF all this checks out and you want to go further, close the decompressors and open the throttle and see if you can get it to light up. This is where your diesel fuel may come in. If the tank is dry, then you will need to add your fuel and bleed the system.

If the owner won't allow any part or all of this, I would simply get back in my vehicle and make tracks away from there.

I also see that there is no scarifier showing in the photos and I can't see if it has rear rippers. If there are no rear rippers, it would be a good idea to ask if the scarifiers are still around, including the draught links, scarifier beam - hopefully with some shanks - the lift links, the gearbox/cross shaft, the lift arms and any missing control drive shafts. If it does happen to have a rear ripper, it will also most likely have some form of hydraulics to control them.

Happy hunting.

[OzDozer]

Jake - The Cat 12 uses mechanical controls to lift and lower the moldboard, and to perform all the other functions.

A driveshaft comes out of the centre of the transmission (the clutch shaft or transmission input shaft, is a hollow tube), and is redirected via a 90° gearbox under the front of the floorplate in the cab, to a vertical shaft that goes into the "power control box" that is mounted in front of the operator, at the lower windshield area.

The power control box splits the drive into 6 driveshafts with matching control levers, 3 each side of the steering wheel. These driveshafts and control levers actuate the moldboard lift and lower, sideshift, circle rotation, and wheel lean, via dog clutches.
A dog clutch is engaged when the control lever is moved, and the driveshaft is locked mechanically once the lever is returned to its spring loaded center position.

This system was used by Cat from the first Cat 12, until the last Cat 12 in the mid-1970's. Cat claimed the mechanical system resulted in better quality grading, as there was no blade "creep", as was common with earlier hydraulic systems. The first Cat graders with hydraulic controls were the all-new design, articulated 120G and 130G in 1972 and 1973.

The Cat graders of this era are money pits if they are worn. They are full of shafts, universal joints, gearboxes, pins & bushings, and wearing parts. The front end (steering and axle) is commonly worn, and can cost big $$'s to bring back to a condition where all the sloppiness is largely eliminated. The same goes for the moldboard lift and lower mechanisms, the sideshift rack, and the circle & A-frame. These are all prone to serious wear that makes accurate grading impossible.

Check out the grader carefully for signs of abuse and serious wear .. such as a twisted moldboard, broken and repaired moldboard supports, twisted or cracked & repaired circle and A-frame, worn shafts and uni-joints, worn gearboxes, sloppiness in the drive mechanisms.

Look for leaks at the chain cases, and stand behind the grader and check to see if the chain cases are vertical, or if they tilt in at the top. Tilted chain cases indicate serious wear. Check the rubber depth and tire condition. A set of tires will set you back nearly half the value of an old grader. Engine condition check is the same as any other machine .. look for easy starting, blowby, leaks, repairs, cooling system condition. Good luck, most of these old Cat 12's aren't worth much now.