the machine ( 2000 CAT 312b) seems to always be in high gear and doesn't go into low gear. When i'm going up a hill it starts dying down quickly and it seems to jam and slows down alot, but the machine never changes gear, its always on high gear. Have you encountered anything like this, can you tell me what I should check or change
Hi, Its Dan again. I just answered this on your old question. I will repost the answer here.
If you cannot change speeds on your monitor panel (turtle and rabbit) then check your wiring and your switches on your main control valve. You will have two travel switches at the travel section on the main valve. Follow your lines back to the valve from your swivel. The switches will be on the valve in that section. To check your travel motors, remove the inner guards, Disconnect and cap the case drain line ( low pressure ) You will have 2 high pressure lines, a brake signal line(smallest) and the low pressure case drain that returns to tank. Cap it with a hydraulic plug, adapt a long hose to the fitting on your drive motor into a bucket, pin your track at your sprocket so it wont move, at an idle move that travel lever and if the oil sprays out under pressure than your drive is bad. It should leak some into the bucket but not spray to the other side of the machine under pressure. Thanks for using JA
1995 Wyo-tech graduate 17+years shop/field experience/on all major brands of heavy equipment and trucks.