My ’89 Chevy G20 with 5.0 radiator is shot, a slow leak, no saving it. I bought a Murray 433709 at O’Reillys. It’s the correct unit except for one problem. The female thread on the radiator for the oil lines is 5/8 inch diameter. The old radiator has 1/2 inch diameter fittings. This I discovered after trying to install it. I got the lines in place, but they wouldn’t tighten down of course. The tension of the fluid line made it difficult to realize it was the wrong size. Then I had the bright idea to take it back out and measure the openings. Just by eyeball with a machinists rule it’s obvious.

I went back to O’Reilly’s, they have no information on the thread size in their computer description of the various models that fit my van. I didn’t measure the male thread on the fitting, it is brass flare type on that segment.

The existing radiator is aftermarket also from O’Reilly’s, almost certain. The variation in fitting sizes is curious. I did not have this trouble the first time around.

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Te futueo et caballum tuum

1986 300SDL, 362K
1984 300D, 138K

There has to be a simple adapter for that.

^ free idea

But was there a question for us buried in the OP?

You can buy the fittings right at the same orielly on the aisle that has all the little adapters, pipe nipples etc. The counter person may or may not know of your concern, all they know is (here is the radiator, the computer says its a full assembly)

I have a jar of those at hand (collected from scrapped cars) and they come in 2 diameters even direct from GM and to further muddle them, they come in metric and imperial (real old timey stuff), I dont change them anymore, I just swap the internal O ring for a new one and its good as new.

MB also used the same fittings on some models.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

Well that sucks out loud .

As mentioned there are often *some* brass fittings i drawers or hanging on spinning racks, maybe there's a commercial hose shop near you ? .

They'll have whatever you need to adapt it as will places like Summit Racing .

I feel you pain ~ I need to be able to eyeball things and loved the hundreds of drawers full of fittings in the commercial shops I used to work in .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

I should check back in on this. I’m a little embarrassed to admit that I was mistaken about what was going on.

This is the female side of the two fittings that the radiator came with.



Here is the male part of the fitting:



I screwed this one out of the radiator, the hole it came out of looked pretty small.

I found the following part at an O’Reillys. I liked the name of it, it sounded like what the sleeve nut on the tranny fluid line would be called. Also, the thread diameter was about 1/2 inch which is what I measured in the old radiator:



I had the old radiator with me - it screwed into the radiator very nicely. So now I was making progress. It had been frustrating not having a sample of the male thread to haul around with me. The only two I previously had were inextricably linked to the radiator lines of course.

And then I happened to notice that the threads on the “tube nut” in the last photo looked similar to those on the piece you can see in the second photo. So I tried screwing that piece also into the old radiator, and whoops, it also fit very nicely. So I had the right radiator all along. All I can guess is that it came with those fittings in place because they’re needed for some other vehicle.

I feel a little bit dumb, the good news is my van is running great and leak free at long last.

__________________
Te futueo et caballum tuum

1986 300SDL, 362K
1984 300D, 138K

Don't feel dumb, feel smart that you learned something new .

I've bought a few Chinese radiators that simply didn't work because they had different hose nipples than the correct one .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

It’s funny, I had been thinking that they should have included the adapters I had in mind. When in fact they apparently included adapters for another vehicle to use the same radiator that had different transmission fluid lines.

HAH!

Perhaps an attached note, specifying what the adapters were there for might have been useful.

__________________
Te futueo et caballum tuum

1986 300SDL, 362K
1984 300D, 138K