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Late model GM returnless pump
Posted to Technical Theory Forum on 4/24/2009 24 Replies

I had the privilege of replacing and doing a failure analysis on this fuel pump. In the process I grabbed some photos to share the design with everyone. It is a returnless system with a lifetime filter in the module. It has a pretty neat jet pump setup to keep the module filled to the very end.

Here is the assembled pump. Notice the fuel pressure regulator is on the outlet side of the filter. Also note that the outlet of the regulator drops into a tube. That tube is a part of the jet pump setup. On the bottom of the module there is a jet pump inlet which sucks fuel up the other tube and into the module. On the left tube it is open to the bottom of the tank. The right tube has the 90 degree fitting that goes under the left tube and has an orifice in it that faces up. That orifice is like a high pressure nozzle that causes the fuel around it to flow upwards and into the module.

The bottom of the module has the typical check valves that allow fuel to flow in if the fuel level in the tank is higher than the level in the module.

The fuel filter is pretty basic.
The top is sealed to the housing with an o-ring and the filter media is a paper/fiber composition. Fuel flows from the outside in. There is not a bypass valve of any kind should the filter become plugged.

The fuel pump itself is just your basic style. The strainer fits inside the module and unlike other designs there isn't a strainer outside the module.



Andrew from Utah

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car Vehicle Data

2006 Chevrolet Silverado 1500 LS 5.3L

Engine5.3 L
Trans4-speed Automatic (Electronic)