Is there anywhere other than the dealer to obtain one? What should I expect to pay for one? I've tried the usual, NAPA, Advance, AutoZone guys, they all look at me like what the H--- are you talking about. Anybody got a GM (or any other)part number? Thanks

I'd try scrap yards and maybe some garages that do diesels may have one lying around. This is not an item you really ever see fail, just needs to be cleaned occasionally.

What is best method to clean it. I was told it should be replaced every 30,000 miles? I am replacing the Vac pump that has been dumping oil down the backside of the block for over a month now, and thought that a bad CDR could be the cause of it's failure. Inside of the intake is certainly oiled up heavily. Any suggestions on how to clean that, short of removal? Thanks again.

removal is the only way, otherwise you just wash that crud into the heads. Just soak the CDR in diesel fuel or naptha or pretty much any available solvent to break up the oil/carbon deposits inside. The CDR has nothing to do with the Vacuum pump, are you talking about the EGR? I also don't see how you could be leaking oil from the vacuum pump, since there's no oil supply to it.

Early vac pumps were part of the oil pump drive - pressurized engine oil lubricated the drive shaft bushings, and the crank bearing.

Leaks at housing-to-block gasket, pump-to-housing o-ring, and at pump diaphragm plunger seal.

my mistake, I was thinking belt drive, he's right, early ones used the oil/tach drive.

There is a brand new CDR valve on ebay right now that fits 89 and up 6.2/6.5. do a search for 6.2 diesel.;)

That CDR may not fit the '82 system, which had the breathe-thru filler cap, and rubegoldbergian kluge of pipes and hoses.

Need to compare the picture with what is actually on the engine, particularly the hose\fitting diameters.

OR, for a real fix - the '88-up J intake, valve covers, and oil filler tube would improve your situation.

Lastly - all CDR cans are not created equal - the Turbo 6.5 gets an 'enhanced' spring and diaphragm, will not function at all on a normally aspirated engine.:cool: