641 & 651 TRACTOR-SCRAPERS Controls Caterpillar


Controls
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1.1. Tractor Individual Wheel Brakes
2.1. Differential Lock
3.1. Hydraulic Retarder
4.1. Bowl
5.1. Apron
6.1. Ejector
7.1. Transmission Hold
8.1. Cushion Hitch
9.1. Bowl-Apron

Tractor Individual Wheel Brakes

Push handle forward to apply tractor right wheel brake.

Pull handle back to apply tractor left wheel brake.


NOTICE

Do not use tractor individual wheel brakes to steer tractor.


Differential Lock

Depress pedal to lock differential.

Release pedal to unlock differential.


NOTICE

Do not attempt to turn tractor when differential lock is applied.


Hydraulic Retarder

Pull lever back to apply retarder.

Push lever forward to release retarder.

Anticipate the use of the retarder. Three or four seconds are needed to engage the hydraulic retarder once the lever is moved. Handle position determines the amount of retarding. The farther back the handle, the more braking action. Use retarder at least once a week to keep seals lubricated.

Bowl


(1) RAISE

(2) HOLD

(3) LOWER

(4) QUICK DROP

Apron


(1) RAISE

(2) HOLD

(3) LOWER

(4) FLOAT - Control will lock in this position until moved manually.

Ejector


(1) FORWARD

(2) HOLD

(3) RETURN - Control will lock in this position until ejector returns to rear or another control is engaged.

(4) OVERRIDE - Fast return.

Transmission Hold

Depress pedal to lock transmission in desired gear speed.

Release pedal to allow transmission to shift automatically.


NOTICE

Do not downshift when transmission hold is depressed.


Cushion Hitch

Pull up on control for CUSHION RIDE.

Push down for hitch LOCKDOWN.


NOTICE

Be sure hitch area is clear of obstructions.


Bowl-Apron

Push handle forward to lower apron.

Handle in upright position is HOLD.

Operation of standard apron and bowl controls is the same. (See page 12.)