768 & 772 TRACTORS Moving The Tractor Caterpillar

Moving The Tractor
1.1. Emergency Brake System
2.1. Checking the Emergency Brake System
3.1. Changing Gear Speed and Direction
1. Fasten seat belt.

2. Be sure trailing unit control is in the FLOAT position.

3. Push emergency brake lever forward, if equipped. (See page 24 for additional information.)

------ WARNING! ------

Be sure area is clear of personnel and obstructions.


4. Push extended braking control lever forward.

5. Push trailing unit brake control lever forward to release brakes.

6. Pull parking brake lever back to release brake and transmission control.

------ WARNING! ------

Do not move tractor without normal air pressure.


7. Move transmission control to desired direction and speed.

8. Depress accelerator.

NOTE: The 768 engine can be started with transmission lever in position other than NEUTRAL, but tractor will not move. To release the transmission safety valve move the lever to NEUTRAL for a few seconds, then to desired direction and speed. The 772 will not start when the selector lever is in other than neutral.

Emergency Brake System

1. If buzzer sounds or low air pressure light comes on, stop the tractor.

2. To stop the tractor, depress service brake pedal.

3. If the service brake will not stop the tractor, pull emergency lever. Be prepared for a sudden stop.

4. When tractor is stopped, wait until air pressure returns to NORMAL. If air pressure does not reach NORMAL, have the air system checked.

------ WARNING! ------

A horn will sound when emergency reservoir pressure drops below safe operating pressure. Brakes will then automatically apply and stop the tractor.

The emergency brake may be applied and released 3 times with a dead engine, after which the brakes will automatically remain applied.


Checking the Emergency Brake System

Periodically check the operation of the emergency brake system.

1. Stop the engine when the air system is at normal operating pressure.
2. With the front brakes switch ON, pump the service brakes to decrease air pressure to 60 PSI. At this pressure, the low air pressure warning buzzer and light should actuate.
3. Apply the emergency brake control lever two times. At the second application, the emergency warning horn should sound.
4. After the third application of the lever, the brakes should remain applied.
5. Start the engine and fill the air reservoirs to operating pressure.

Changing Gear Speed and Direction

Machine must be stopped and engine at low idle when changing direction.

Operate engine between 1200 and 2200 RPM. On downgrade it is permissible to operate between 2200 and 2350 RPM. Never exceed 2500 RPM.

When under heavy load, upshift when speedometer indicator reaches maximum point of each color range. When under light load, upshift at about 1600 RPM.

Downshift only when speedometer indicator is at the minimum point of each color range and when downshift indicator is ON.

Move transmission control with a single, quick motion.


Improper downshifting can cause sudden reduction in travel speed and overspeeding of engine. Keep torque converter temperature gauge in NORMAL operating range.

Never allow machine to coast downgrade. Keep transmission engaged.