1956 Buick Power Steering Fitting Size

Hi all,

Would anyone happen to know offhand the size of the male fitting on the steering box side of the pressure hose? 5/8"?

I'm not at home but would like to order some parts for a conversion I'm working on.

Here's a picture for reference (hose on the left): https://lh5.googleusercontent.com/-QQhFtOXxt-k/TyM2ysY8n0I/AAAAAAACn_Y/8H5i4dwZkXY/w1248-h836-no/P0005821.JPG

Thanks

Pressure side is a 7/16-20 thread.

Thanks Dan. That seems very small for a power steering line. I need to step up to a 5/8-18 thread, any idea how I can go about doing that? I can't seem to find a conversion bushing.

Also, would you happen to know the pump side fitting specs?

5/8-18 is the size of the return fitting. The problem you're going to run into trying to find that fitting is it will have to be flared on both ends, and be able to handle 800+psi. Personally I would go to a local auto parts store that has a hydraulic hose crimping center and have them make you one.

The gear side is 7/16-20

The pump fitting is 5/8-18 (female fitting on the hose)

The gear I plan to use has a M18X1.5 (o-ring style) pressure fitting. I found an adapter to convert it to 5/8-18 (inverted flare) - Gates part number G49702-1806. I was hoping that the Buick pressure side fitting was 5/8 as well. Looks like I will have to go custom as you suggest. Can the new hose be the same size all the way across, or should it have a step down like the original?

It will likely be the same size rubber hose all the way to each fitting. You will have to talk to the parts place you go to and see what they have the ability to make. The good news is they should be able to put the M18x1.5 o-ring fitting on one end and the female 5/8-18 on the other so you wont have to mess with adapters.

Sounds like a plan. That 5/8-18 female flare fitting has been a chore to find online, hopefully my local hydraulic place will have something. Is it a regular inverted flare?

Yes it should be.