Fuel Splash from Filler Neck after Filling Tank after 04-06-04-003 on 03 and 04 Buick Rainier, Chevrolet Trail Blazer, GMC Envoy, Oldsmobile Bravada- kw 4.2 5.3 gas fill tank hard hose NNK pipe pump

The following diagnosis might be helpful if the vehicle exhibits the described symptoms in the PI.

Immediately after filling the gas tank, gas may "spitback" or splash out of the filler neck.

If this concern still exists after installing the updated upper fuel tank filler pipe and lower hose assembly from bulletin 04-06-04-003, make sure that the lower hose assembly is positioned properly. The updated lower hose assembly contains an internal "flapper" valve that moves on a floating hinge. The hinge should be in the 12 o'clock position once the lower hose is installed. Since the hinge is not spring loaded, the "flapper" valve may stay open if the hose is mis-positioned during installation which may cause a repeat concern.

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Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance.

(2003 Chevrolet Trailblazer EXT and GMC Envoy XL Long Wheelbase Models) and (2003 Chevrolet TrailBlazer, GMC Envoy and Oldsmobile Bravada Short Wheelbase Models with RPO NNK - 22.5 gallon tank) and (All 2004 Chevrolet TrailBlazer, GMC Envoy, Buick Rainier and Oldsmobile Bravada Short or Long Wheelbase Models Built Prior to December 1, 2003)

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