Master Cylinder bore size?

slantsixdan said
No, the WC37696 has 3/8"-24 brake line thread, though I do see where RockAuto incorrectly lists it as having 10mm. The WC113704 had 3/8"-24, too, but that no longer matters; it's obsolete/NLA.

(I installed my first set of WC37696s in an A-boody almost three decades ago, and the car's original brake lines threaded right on in. That post I linked has been up almost that long, and nobody who's followed it has discovered metric threads on their new cylinders.)

Got it, thanks for explaining.

I think it might actually be Raybestos providing the bad information to the websites. I saw the incorrect metric sizing listed for the Dorman version of the WC37696 on a different site (PartsAvatar.ca: Canada Online Auto Parts, Body Parts & Accessories), but on Rock Auto the bore sizing for the Raybestos WC37696 wheel cylinder shows as being 0.594" which is... 19/32"??? Seems like a weird size (because it's wrong!).

Some double reverse backwards searching has identified that the 1987 - 1999 Dakotas used the Raybestos WC37696. Looking up that vehicle on Rock Auto shows there are about a dozen options, some for 10" drums and some for 9" drums. They all show that the 10" drums use the 13/16" bore wheel cylinder, and the 9" drums use the 3/4" wheel cylinder. Except for the Raybestos and Dorman options, but again, their parts are probably fine and it's just information that's wrong.

So it looks like the 90s Dakotas are a good reference vehicle to use when the guy at the parts counter gives me that blank stare after I tell him I want a 13/16" bore wheel cylinder for an old Dodge!