Pressure Control

Control Board

Removal

Display connector

Engine, ground and clutch wires

4.Remove four screws (169c) and control board (169b).

WARNING

Read Skin Injection Hazard, page 3; Burn Hazard, page 4

1.FIG. 10. Remove two screws (71) and swing down cover (169a)

2.Remove strain relief bushings (123a and 123b).

3.Disconnect at control board (169b):

Lead from potentiometer (169d)

Lead from transducer (66)

Lead from WatchDog switch (169g)

Lead from ON/OFF switch (169f)

Lead from gallon counter sensor (pump stroke)

Installation

1.FIG. 10. Install control board (169b) with four screws (169c).

2.Connect engine wires to control board (169b).

3.Install control box (169a) with four screws (71).

4.Connect at control board (169b):

Ground and clutch wires

Display connector

Lead from gallon counter sensor (pump stroke)

Lead from ON/OFF switch (169f)

Lead from WatchDog switch (169g)

Lead from transducer (66)

Lead from potentiometer (169d)

5.Install new strain relief bushings (123a and 123b).

6.Swing up cover (169a) and secure with two screws (71).

Pressure Control Transducer

Removal

WARNING

Read Skin Injection Hazard, page 3; Burn Hazard, page 4

1.FIG. 10. Remove two screws (71) and swing down cover (169a)

2.Disconnect transducer (66) lead from control board (169b).

3.Pull transducer connector through rubber grommet (113).

4.Remove pressure control transducer (66) and o-ring (67) from filter housing (72).

Installation

1.FIG. 10. Install o-ring (67) and pressure control transducer (66) in filter housing (72). Torque to 35 - 45 ft-lb.

2.Install transducer connector and rubber grommet in control housing.

3.Connect transducer (66) lead to control board (169b).

4.Swing up cover (169a) and secure with two screws (71).

Pressure Adjust Potentiometer

Removal

WARNING

Read Skin Injection Hazard, page 3; Burn Hazard, page 4

1.Fig. 13.Remove two screws (71) and swing down cover (169a)

2.Disconnect potentiometer (169d) lead from control board (169b).

3.Loosen set screws on potentiometer knob (169h) and remove knob, shaft nut, lock washer and potentiometer (169d).

4.Remove shaft spacer (169e) from potentiometer.

Installation

1.Install shaft spacer (169e) on potentiometer (169d).

2.FIG. 10. Install potentiometer, shaft nut, lock washer and potentiometer knob (169h).

a.Turn potentiometer shaft clockwise to internal stop. Assemble potentiometer knob (169h) to strike pin on cover (169a).

b.After adjustment of step a., tighten both set screws in knob 1/4 to 3/8 turn after contact with shaft.

3.Connect potentiometer lead to control board (169b).

4.Swing up cover (169a) and secure with two screws (71). Digital Display Messages

311046H

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HP GMAX 5900 manual Control Board, Pressure Control Transducer, Pressure Adjust Potentiometer