ST300 Transmission Line Install Question

[jsboots]

Hi all.  Getting closer to firing the 65 with a fresh 401.  When we purchased the car the motor, trans, cross member, and lines were all removed from the car.  We have the drivetrain finally installed and was installing the transmission lines.  It appears the lower line needs a 90 degree fitting to clear the lower hose outlet.  The line is prebent that way and doesn't look like if I straighten the line that it will clear the radiator hose.  I don't see any info on a fitting that goes in the lower fitting.  The radiator is the correct cross flow.

Any help would be appreciated.

[TrunkMonkey]

If the ST-300 was from a Skylark or Special, and has the lines, they likely do not have the same bends as the GS.

Hope the image helps.



The 90* elbow I think, is a 7/16 NPT to the radiator and might be an inverted flare to the line.

[jsboots]

The illustration definitely helps.  I have the correct lines I am just missing the 90 Degree fitting.  The thread size is 1/2-20 to the cooler but I can't find the correct fitting.

[TrunkMonkey]

Do you know the size of the line fitting?

[jsboots]

Measured 1/2-20

[WkillGS]

Going from memory (so don't count on it being correct!). I think it's a 'Inverted Flare Fitting-Brass Elbow-Male'. Inverted flare to accept the line, NPT male into the rad.
Check your local auto parts store or a hardware or plumbing supply.

[TrunkMonkey]

Going from memory (so don't count on it being correct!). I think it's a 'Inverted Flare Fitting-Brass Elbow-Male'. Inverted flare to accept the line, NPT male into the rad.
Check your local auto parts store or a hardware or plumbing supply.

That's what I think.

the 1/2-20 might be the radiator female, but I think it's NTP, and the line should be inverted flare, but need to be certain of them both.

I have a source that does custom hydraulic and pneumatic line manufacturing and they have an "old world" warehouse of shelves of cardboard boxes with fittings from when Christ was a Corporal.

I will be happy to help find the fitting and send it on at no charge to the OP if the exact type of fitting and thread can be determined.

My application is a 1964 Skylark, pulled the 300v-8/ST300 and put in a nailhead with T-10, so my ST-300 Oil cooler line/fittings might be different. But I have the '65 GS radiator and can get the thread/fitting for that, but I do not have the line fitting from the tranny for the GS (in case it is different from the 1964 Skylark).

[jsboots]

I will get a 1/8 NPT in town to confirm that is what goes in the radiator.  The fitting on the end of the transmission line is definitely 1/2-20 thread.  So that is a 5/16" line inverted flare?

Appreciate all your input!

[TrunkMonkey]

Yes. Should be 5/16.

Can you get a picture of the end of the tube and the fitting on it and also the bung on the radiator?

I looked at mine and the top and bottom bungs on the radiator are inverted flare and not pipe.
(I have manual trans, so never looked at them closely before)

Looks like 12-1/2 x 5/16 inverted flare.

[Brian]

From what I remember, the 90 deg fitting is soldered into the radiator at the factory.  Could have just been the one I was looking at had been soldered in after the fact though. 

[gs spoken here]

My 66 4 speed car had the lower 90 deg, soldered in, with plugs in both.

[jsboots]

Last night I was able to review the fittings and thread type.  The transmission line is 5/16 line with 1/2-20 thread and the female input on the radiator is 5/16 inverted flare also 1/2-20 thread.  I can't find any 90's or elbows with the same thread count.  I tried installing a 1/4 NPT into the radiator by hand and it would not start.  Should I use a 1/4 NPT male elbow with 5/16 inverted female and chase the threads to 1/2-20 and solder into the radiator?

The radiator could possibly be an aftermarket but the inlet/outlets appear to be correct for the a/c car.

I am attaching pics.

[TrunkMonkey]

Those are the same type fitting on my radiator.

Thanks for posting the fitting sizes. I'll see if I can find the correct 90 and post here.

[WkillGS]

Looking at the Eaton/Weatherhead catalog, I don't see much with a male inverted thread. May be best to call tech support. See page 36:
http://www.eaton.com/ecm/groups/public/@pub/@eaton/@hyd/documents/content/pll_1015.pdf

[Brian]

You can get a 5/16 male inverted to hose bead elbow.  One option would be to get one of them, cut the hose bead off of it, cut the female end off of a pipe thread to 5/16 female inverted flare elbow, then you can braze them together with a torch and some brazing rod.