C2 Oil Pump Rebuild

[Donald T.]

Looking for specifics on how I can rebuild an oil pump to reduce oil pressure to pass PV. I have already replaced the pump with a standard Melling M-55, so just replacing the relief spring probably won't help. The engine must have been rebuilt with tight tolerances. I run about 45 PSI at warm idle and jumps to 60 upon acceleration. I have already put nearly 2,000 miles on the motor since the rebuild, so it is already broken in. I have also double checked the gauge with two different test gauges, and the high reading is accurate.

Thanks!

[Duke W.]

Re: C2 Oil Pump Rebuild

I don't think "tight" clearances is an issue. Even if the pump output was completely blocked, the relief valve should open at 40-45 psi hot.

I think your pump has the wrong relief spring.

Maybe you should just buy a correct OE replacement pump from the Sealed Power or Clevite catalogs.

There seems to be a lot of "problems" with Melling pumps. I recommend others to avoid them. Go with the known Federal Mogul and Dana Corp OE replacement brands.

http://www.federal-mogul.com/en/AftermarketSolutions/NorthAmerica/TechnicianResources/Catalogs/Catalogs.htm

Duke

[Donald T.]

Re: C2 Oil Pump Rebuild

Thanks Duke! That make sense. I will that a try that and see what happens.


Thanks!

Don

[Donald T.]

Re: C2 Oil Pump Rebuild

Duke was on the money as usual! I replaced the relief spring with the correct GM part. The gauge would hit 60 PSI at start up, and now it doesn't exceed 45. Warm idle is now running 30 - 40 PSI.

Thanks!

Don