Hi all, looking for a little help on a machine I'm trying to sell. I have a cat 12 motorgrader that has seen some better days but has treated us really well for the last 20 years. it has been parked for the last 8 since we (me and my father) bought another 12 that is in exceptional shape. we decided to let the old one go so I got it running a couple months ago. now the issue I'm having is with the throttle linkages. The throttle quadrant was seized when I got in it this spring and I finally got it unstuck and kind of working but the throttle pedal stays on the floor at idle and is up at full throttle and decelerates the engine when depressed. I know that's not right, and the only linkage I had apart was the 90 deg. swingarm under the floor that the quadrant linkage attaches to. I looked at the other machine and its linkage and governor setup it completely different all together.

AS far as I can tell on the machine in question the throttle arm the goes into the governor housing on the pump rotated all the way clockwise (pushed back) is the closed/off position correct? and counter clockwise is full throttle (arm pulled forward) anyone have pictures of the correct setup or seen this? Dad cant remember if this was always the way it was, and neither can I. All he says is he bought it wore out and is selling it wore out, and I haven't run the machine since I was probably 15 so I cant remember, but not having a working throttle is annoying, and I have a guy interested and I'd like it to work.

That is exactly how it is supposed to work.

Does the throttle pedal in the floor have a heel and toe movement? The 12e grader has that where you can use it to decelerate with your heel or accelerate with your toe.

I could see the utility of a straight decelerator pedal in operation of the grader. They’re pretty common on other equipment. I don’t have any experience with an 8T. Used to have a 1953 212 but I don’t remember if it had anything but a hand throttle.

Hi Team,
8T1 to 8T 14781 had a single pedal Decelerator pedal that I seem to recall goes up and down with the hand lever position-- the grey OMI Operators book shows the pedal fully up above the floor at the full speed position--I always found these odd to operate at first when learning to drive them at The Dealer as an Apprentice--IE, push pedal down to go slower.

8T14782 -up use the familiar heel and toe style pedal such as mentioned above for the 12E Graders.
Cheers,
Eddie B.

My 8T only has decelerate on the floor pedal. Decelerate when shifting.