GAC QST30 Conversion — Installing ADD175 Electric Actuator on Fuel Pump
For the GAC QST30 Conversion.
Applies to: GAC QST30 Conversion
Before you start
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Procedure
- Remove the upper actuator cover and O-ring seal. Save all hardware.
- Clean the actuator to pump adapter mounting surface so it is free of any debris.
- Insert two M6 X 16 mm long screws and spring washers through the lower mounting holes inside the upper actuator cavity.
- Align the gasket and install it over the two screws and carefully slip the actuator over the fuel rack assembly until the two lower screws just start to meet the fuel pump mounting holes.
- Insert a ball end hex wrench through the access point located on the operating lever and tighten the left lower mounting screw a few turns.
- Pull the operating lever outward and slide the ball end hex wrench into the space between the operating lever and the access point in the housing of the actuator and tighten the right lower mounting screw.
- Once these two screws are fully engaged into the pump housing, insert two additional M6 X 16 mm long screws and spring washers into the top two mounting holes of the actuator and thread into the pump housing. Torque all four mounting screws to 5-6 N·m (44-53 in-lb).
- Verify the fuel rack assembly moves in and out freely inside the upper cavity of the actuator by moving the fuel shutoff lever.
- Carefully loosen screws over the slotted portion of the adjustment plate so the operating lever bearing assembly can be moved away from the fuel rack connection link. Ensure the fuel rack is as far out of the pump as possible.
- Rotate the operating lever out from the actuator until it stops. The armature of the actuator will be in contact with the lower cover. Hold in this position.
- Rotate the adjustment plate and lever bearing assembly in towards the fuel rack so contact between the bearing and rack connection link is made. Continue to push in an additional 1 to 2 mm.
- While holding this position, torque the operating lever assembly shaft screw and screw to 4-6 N·m (35-53 in-lb).
- Inspect the assembly to ensure all screws are tight and the fuel rack moves smoothly without any binding.
- Push in the fuel rack manually to the full fuel position and rotate the fuel shut off lever to the minimum fuel position to confirm the shut off lever contacts the metal plate on the fuel rack connector assembly and forces the fuel rack to minimum position.
- The operating lever has a maximum fuel adjustment set screw which can be used to restrict the fuel rack travel. Set the fuel adjustment screw and torque the locknut on the fuel adjustment screw to 5-6 N·m (44-53 in-lb).
- Install the top cover and O-ring seal. When installed, the cover must not hit the internal operating lever or the maximum fuel adjustment screw.
- Apply Loctite 222 to the six cover screws. Torque the cover screws to 2-3 N·m (18-27 in-lb). Check for any oil leaks.
- Lock-wire the lower screws for tamper resistance.
Tools required
- Ball end hex wrench
- Filter wrench
Specs & torque values
- M6 X 16 mm screws and spring washers
- Mounting screw torque: 5-6 N·m (44-53 in-lb)
- Operating lever shaft screw torque: 4-6 N·m (35-53 in-lb)
- Fuel adjustment locknut torque: 5-6 N·m (44-53 in-lb)
- Cover screw torque (with Loctite 222): 2-3 N·m (18-27 in-lb)
Source: manual:175 Series QST30-Conversion-Solution-A5-1.pdf. Figures and steps are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.