CDR Valve Part Numbers ???

[PeteRock]

I'm looking for the correct CDR part number for my engine. It's a 6.2 in a 1983 GMC vandura. GMPartsDirect.com lists two parts for that year:

Part # 25042248 ID # CV870 $41.55 (w/ s&h)
Part # 25042462 exc ID # CV870 $22.88 (w/ s&h)

The one in my van now is

Part # 25042443 ID # CV871


Anybody know the difference between the above parts? Its listed as a special order, non-returnable part, so I want to make sure I get the right one.

Thanks for your help,

-Pete

[BobND]

Rock Auto concurs with your post...

CV-871 = 25042462


https://www.rockauto.com/dbphp/mfr,ACDELCO,EMISSION,5052,PCV+VALVE


(Scroll down on the linked page for the cross-reference.)

[PeteRock]

The pictures of the CV870 and CV871 on the Rock Auto site both look very similar. Anybody know what the real difference is (besides the 870 being twice the price). Is the 870 better, or just for a different application?

Any idea how to verify which one is supposed to be on my engine? I bought the van used, and I don't want to assume anything about the parts that are in it now. If the CDR's been replaced with a cheaper part, I'd rather find out now and fix it right... although, if it's the right part, I don't mind the savings.

Thanks again for your suggestions.

-Pete

[BobND]

Pete, I would bet the only difference between the two is the angle of the fitting(s).

The "guts" are almost certainly exactly the same... all there is in there is a thin diaphragm and a light spring.

I have a couple laying around the shop of various part numbers. If I get a minute later, I'll see what numbers are on them. and how they compare in appearance.

I would order the one matching the number of the unit you now have installed.

Are you replacing it because there is an oil leak through the cover of the CDR, or replacing it hoping to reduce oil consumption?

[PeteRock]

I'm getting ready to replace the rear main seal. It's been leaking pretty bad for a while, and I'm getting tired of dumping oil all over the driveway. I don't know when the CDR was last replaced, so I figured I'd change it out when I do the seal as a precaution to avoid blowing the seal out again.

[BobND]

Pete,

If your 1983 is all-original, I think it will have a fabric rope rear seal, and they just simply deteriorate over time. I recently replaced one that was completely missing, except for a few remaining threads.

Experience tells me this is very likely the cause of the leak, rather than a bad CDR, but it certainly can't hurt to replace the CDR... it's likely got a few years on it!

The new seal (Fel-Pro) will be silicone rubber.

Take a good look at the main bearing inserts while you're in there. Worn bearings contribute to shaft movement, and also excessive oil flow past the bearings, both of which can make the new seal more prone to leak.