# 1991 Caterpillar 12G **URL:** > This machine has been sold or is not currently for sale. ## Listing details - **Price:** Sold - **Listing ID:** 89105661 - **Year:** 1991 - **Manufacturer:** Caterpillar - **Model:** 12G - **Category:** Motor Graders - **Hours:** 17253 - **Serial number:** 61M14265 - **Location:** Anderson, IN ## Description Defroster Fan, Differential Lock, Lighting, Moldboard Size - 12', Online Owner's Manual , ROPS - Enclosed, Throttle Lock ## Machine details ### GENERAL CONDITION - **Machine Starts and is Operable:** Yes - **Tires are Aired Up and Drivable:** Yes ### GENERAL APPEARANCE - **Cab or Canopy:** Good - **Fuel Tank:** Good - **Grab Irons:** Good - **Paint:** Good - **Steps / Ladder:** Good ### SAFETY ITEMS - **ROPS Certification Plate:** Yes ### OPERATOR STATION - **Dash Console:** Good - **Gauges:** Good - **Switches:** Good - **Windshield Wipers:** Poor ### ENGINE - **Apparent Other Engine Damage:** No - **Blow By:** No - **Fuel Leaks:** No - **Knocking:** No - **Oil Leaks:** Yes - **Water in Oil:** No ### COOLING SYSTEM - **Belts / Pulleys - COOLING SYSTEM:** Good - **Fan:** Good - **Water Pump:** Good ### ELECTRICAL, STARTING AND CHARGING SYSTEM - **Alternator:** Good - **Batteries / Cables:** Good - **Starter:** Good ### TRANSMISSION - **Leaks - TRANSMISSION:** No - **Transmission - Noisy:** No ### STEERING - **Articulate P & B:** Good - **King Pins:** Good - **Steering Cylinder:** Good - **Steering Linkage:** Good - **Tie Rods / Rod Ends:** Good - **Wheel Lean Cylinder - STEERING:** Good ### BRAKE - **Compressor:** Good - **Control Valve:** Good ### DRIVECHAIN / TANDEMS - **Wheel Lugs & Rims:** Good ### HYDRAULICS - **Leaks - HYDRAULICS:** No ### BLADE - **Circle A Frame:** Good - **Face / Moldboard:** Fair ### TIRES - **Notes - TIRES:** Rear tires are in generally good condition. Fronts are marginal. ## Manufacturer specifications ### Circle - **Blade Tip Angle - Front:** 90 degrees - **Blade Tip Angle - Rear:** 90 degrees - **Diameter:** 60.3 in (153.16 cm) - **Max Lift Above Ground:** 17.3 in (43.94 cm) - **Max Reach Outside Tires - Left:** 72.1 in (183.13 cm) - **Max Reach Outside Tires - Right:** 73.7 in (187.2 cm) - **Rotation:** 360 degrees ### Dimensions - **Blade Base:** 8.44 ft (2.57 m) - **Height:** 10.75 ft (3.28 m) - **Height To Top Of Isomount Cab:** 10.93 ft (3.33 m) - **Length:** 27.25 ft (8.31 m) - **Overall Length:** 27.27 ft (8.31 m) - **Tandem Axle Wheelbase:** 4.99 ft (1.52 m) - **Weight:** 29860 lbs (13544.28 kg) - **Wheelbase:** 19.43 ft (5.92 m) - **Width:** 7.75 ft (2.36 m) - **Width Over Tires:** 7.91 ft (2.41 m) ### Engine - **Displacement:** 640.8 cu in (10500.85 cu cm) - **Engine Make:** 2236 - **Max Power:** 135 hp (100.67 kw) - **Net Power Gear 5-6:** 135 hp (100.67 kw) - **Number Of Cylinders:** 6 - **Power Measured @:** 2200 rpm ### Front Axle - **Ground Clearance:** 2.1 ft (0.64 m) - **Oscillation - Total:** 32 degrees - **Wheel Lean:** 18 degrees ### Hydraulic System - **Pump Flow:** 51 gpm (193.04 lpm) - **Pump Type:** closed-center, constant-pressure system w/ variable displacement piston - **Relief Valve Pressure:** 2150 psi ### Moldboard - **Max Depth Of Cut:** 17.8 in (45.21 cm) - **Moldboard Height:** 24.1 in (61.21 cm) - **Moldboard Thickness:** 0.9 in (2.29 cm) - **Moldboard Width:** 12 ft (3.66 m) - **Side Shift Left:** 26.4 in (67.06 cm) - **Side Shift Right:** 20.5 in (52.07 cm) ### Operational - **Alternator Supplied Amperage:** 19 amps - **Cooling System Fluid Capacity:** 12.5 gal (47.31 l) - **Fuel Capacity:** 74.8 gal (283.12 l) - **Hydraulic System Fluid Capacity:** 20.1 gal (76.08 l) - **Max Operation Weight - Front Axle:** 9987 lbs (4530.03 kg) - **Max Operation Weight - Rear Axle:** 21605.4 lbs (9800.06 kg) - **Max Operation Weight - Total:** 31592.3 lbs (14330.04 kg) - **Oil System Fluid Capacity:** 7.7 gal (29.14 l) - **Operating Voltage:** 24 V - **Std Operation Weight - Front Axle:** 7870.6 lbs (3570.05 kg) - **Std Operation Weight - Rear Axle:** 20128.3 lbs (9130.05 kg) - **Std Operation Weight - Total:** 27998.8 lbs (12700.06 kg) - **Tandem Case Fluid Capacity (Each):** 17 gal (64.35 l) - **Transmission Fluid Capacity:** 23 gal (87.06 l) ### Steering - **Articulation Angle:** 50 degrees - **Turning Radius:** 24 ft (7.32 m) ### Transmission - **Max Speed - Forward:** 25.5 mph (41.04 kph) - **Max Speed - Reverse:** 25.5 mph (41.04 kph) - **Number Of Gears - Forward:** 6 - **Number Of Gears - Reverse:** 6 - **Transmission Type:** Cat-built direct drive power shift ## About this model The Caterpillar 12G is a motor grader designed for grading, leveling, ditching, and road maintenance applications. Built as part of Caterpillar's G-series lineup, the 12G is commonly used in construction, mining, and municipal work where precise blade control and reliable traction are required. It features a mid-size frame, articulated steering, and a moldboard system suited for fine grading and surface shaping. The 12G is known for mechanical simplicity, serviceability, and durable components. As a used equipment model, it remains relevant in fleets needing a dependable grader for earthmoving, site preparation, and maintenance tasks. ## Photos ![1991 Caterpillar 12G](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz1hOWZhMDQyN2Y0NmEyOWEzODAyNmMzNDNmOTMxNzRjZSYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjczMTU=) ![1991 Caterpillar 12G photo 2](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz1hMzdjYWQ1ZDEzMDdkOWI4Y2YzZTZiNGYyMTg4N2E1YyYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjMzNDg2) ![1991 Caterpillar 12G photo 3](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz1jMjM1ZmVlMTRhMzk2MzIxZDJiMmJhZjMzNmQyOGY5OCYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjQ0OTkz) ![1991 Caterpillar 12G photo 4](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz04MWNiMzViZTFmMWJiYWQwYjJkMjk4ODFlZDE0YTM4MCYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjM4MjU2) ![1991 Caterpillar 12G photo 5](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz1kODFkMTFjODI5NDZmYjhhZGVlNDQ1MjlkOTZkMDFiZiYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjUxMzY2) ![1991 Caterpillar 12G photo 6](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz04NzczNGRiYTBkNTYwMWQ3ZTY1ODNjMGMzMmFlN2FkNyYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjYwNzc0) ![1991 Caterpillar 12G photo 7](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz1lMjFkNGIyYzVkOTlkOWVkZjkwZDNlZjM3ZWM0OTdiZSYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjI5MTk2) ![1991 Caterpillar 12G photo 8](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz1lMTViYmE0ZDk4YWE3Y2U3YzRiZDU2NmJjMGFkY2VlZCYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjM5OTM4) ![1991 Caterpillar 12G photo 9](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz1iMmExYzM2OTFmM2Y3MTRkYjNhZDM0NjQxOWI5ZDU1OSYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjY1MjA4) ![1991 Caterpillar 12G photo 10](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz1iYmY2NmY3Y2MyYzQ5NDFmYjg4MTIyYWVmOTE0MDZhNCYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjIwNDkw) ![1991 Caterpillar 12G photo 11](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz05MmU5ZTNmMGZkYzI1YjhlZmU3OTVhODg5MTNiZDk3YiYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjUwMjA4) ![1991 Caterpillar 12G photo 12](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz1hZTE2MDk1OGMwYTJjOWEyY2MyMzkyN2I0N2M1MGM0MCYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjI1NTI1) ![1991 Caterpillar 12G photo 13](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz04NmIyZDI1NzhmYTZkZjg0OTM4ZjEwYTA5ZWQwY2ViYyYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjE5NTQw) ![1991 Caterpillar 12G photo 14](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz1lZTMxNDJjOGJhYmJkMzExYzdhYTYzYjU3NjMxNWMwZCYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjUwMzQ=) ![1991 Caterpillar 12G photo 15](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz05MzEwOTY2ZWI4OTRmNzVjYjlmZGRkNTkwZDdjMDAxNiYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjIxNTM3) ![1991 Caterpillar 12G photo 16](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz1lMTYwMjg5OWNlYjhlNzQ4ZTMyOTRlYzdiNjMxNjZjOSYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjIwMTcy) ![1991 Caterpillar 12G photo 17](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz1lODE5Mjk2MjAwM2NiZjAxY2QxMDBkMTYyZTI5NzhlZCYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjE3Mjc0) ![1991 Caterpillar 12G photo 18](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz1mZjEwZmJkNmU5ZGUwOGJlYWQwN2E1YmQ5M2I0MmU0ZiYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjU4MzI2) ![1991 Caterpillar 12G photo 19](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz1lN2QxNzZmZmNhNmZkZjM5ZjJiYTNmZTM1MTA3YjlhNyYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjQ1Mjgw) ![1991 Caterpillar 12G photo 20](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz1mNzkwNjRmNTRhY2I5ZDJlZDUxNWJjZDc1NmMxZGMzYiYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjY1MDUx) ![1991 Caterpillar 12G photo 21](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz1iMGZjODEyMjE2MmFhMjAyZWEwMTJiODdjMWY0NzIyMiYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjM4MDc4) ![1991 Caterpillar 12G photo 22](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz1lNzAwMWNhYTc3MDg4ZGNiODJlNjE5YzQ4ZGExZGUzNiYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjUyNzA1) ![1991 Caterpillar 12G photo 23](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz1kZWJlNGQwNGIzZWEzMGUzZmZjZDY1OWIzMzQxMzZkNyYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjkyMzI=) ![1991 Caterpillar 12G photo 24](http://s7d2.scene7.com/is/image/CatUsedProduction/wtk?JHNyYz05MDM1NmNmY2Y2YjIzY2U2OGYyMWRiZTEyOWUyMGRmNyYkdHh0PU1BQ0FMTElTVEVSJTIwTUFDSElORVJZJjU2OTE2)