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For 1990-2009 cars only

Info - Proper Positioning of Fuel Injection Pump Primer Handle After Use

Subject:Proper Positioning of Fuel Injection Pump Primer Handle After Use

Models:1999-2004 Chevrolet W Series Medium Duty Tilt Cab Models
1999-2004 GMC W Series Medium Duty Tilt Cab Models
1999-2004 Isuzu NPR/NQR Commercial Medium Duty Models



The Zexel fuel injection pump has a pump primer handle that is used when bleeding the fuel injection system during service. Whenever this pump primer is used, make sure that the cap (1) of the primer pump handle is fully seated on the pump housing and securely tightened.

If this pump primer handle is not securely seated after use, the handle may work itself loose, pop up and begin to leak over time due to the engine/vehicle vibration (See Figure 1). In extreme cases, the pump handle may possibly become dislodged completely from the housing. See figure 1 below.

After use, the pump primer handle should be pushed down fully and turned approximately five (5) times until tight in order to properly store and secure the primer pump handle (See Figure 2).

Inspect the injection pump periodically to ensure that the primer handle is secure.

Figure 1 -- Injection Pump Primer Handle (Partially Seated)


Object Number: 1372071  Size: SH

Figure 2 -- Injection Pump Primer Handle (Fully Seated)


Object Number: 1372074  Size: SH