Owner's manual

Model 644E Rev. 8/03

Operation

Auxiliary Hydraulic Pressure Release Switch

(If so equipped)

The Auxiliary Hydraulic Pressure Release Switch (1) is located in

the upper bank of switches on the right side of the dash. This

switch is used to release pressure in the auxiliary hydraulic system

before connecting

or disconnecting the Auxiliary Hydraulic

Couplings.

1. Bring the vehicle to a complete stop.

2. Park the vehicle on level ground.

3. Place the travel select lever in the (N) NEUTRAL DETENT position and

engage the parking brake switch.

4. Lower the boom and ground the carriage or attachment.

5. The ignition switch must be in the RUN position. The engine can be either

idling or shut OFF.

6. Press and hold the momentary Auxiliary Hydraulic Pressure Release

Switch for two seconds to release trapped pressure in the auxiliary hydrau-

lic system.

The two auxiliary hydraulic couplings can now be easily connected or disconnected.

NOTE: If your vehicle is not equipped with the “Auxiliary Hydraulic Pressure

Release Switch” the pressure is automatically released, by internal passages, within

the main control valve.

OS21402

OU0501