4656 Fuel Pump Rebuild

[Pat H.]

Does anyone know where I can get a complete proper AC 4656 fuel pump rebuild kit? I have one from Corvette Central and the diaphragm measures on 2 1/4" while the original stamped AC is 2 1/2". This kit looks like a fits all, and I won't use it as many of the components are casting different from the original. I found a GM #5622175. I doubt they still have any of these around.

[Joe L.]

Re: 4656 Fuel Pump Rebuild

Does anyone know where I can get a complete proper AC 4656 fuel pump rebuild kit? I have one from Corvette Central and the diaphragm measures on 2 1/4" while the original stamped AC is 2 1/2". This kit looks like a fits all, and I won't use it as many of the components are casting different from the original. I found a GM #5622175. I doubt they still have any of these around.

Pat------

I would not be too concerned about the OD of the diaphragm. If the peripheral (bolt) holes in the diaphragm line up with the holes in the pump body, that's all that matters. Some GM diaphragms "overhung" the pump body. The "overhang" serves no useful purpose.

You definitely don't want to use any NOS type rebuild kit. These will not have elastomeric (rubber) components that are resistant to today's gas formulations, especially ethanol blends.

[John D.]

Re: 4656 Fuel Pump Rebuild

Pat, Old Time Parts in MN. Has a rebuild kit for ethanol. None of the materials are the same as original. But at least the pump will work with any kind of fuel. A NOS rebuild kit is pretty much worthless with todays gas.
Old Time Parts has a web site. John D

[Rick A.]

Re: 4656 Fuel Pump Rebuild

here is the link

http://www.oldtimeparts.com/