Hey guys!
I'm replacing the single Reservoir MC and looking for fittings for the sucker.

The MC has a 1/2"-20 fitting and a 9/16"-18 fitting. Both are inverted flare. I am trying to track down the fittings to get moving but am struggling to find them. On the Dorman site I find a couple of fittings:
490-543.1 3/16 In. Female to 9/16-18 Male Inverted Flare Dual Brake Line Adapter
-and-
499-015.1 Brake Line Adapter-Dual Brake-3/16 In. x 1/2-20 In.

I find a 490-302 Oversize Tub Nut-Steel-Green-3/16 In. x 1/2 In. x 20 but it doesnt look like its reverse flare and I dont know what a Tub nut, i think it is supposed to be a tube nut. Can anyone identify WTF?

Im beating around on ebay and am finding some info there but hate to buy the wrong dang part. I think I would prefer the brass over the steel fittings.

Any thoughts on whether there is a major difference in the tube nut over the brass fitting?

Thanks
John

_________________
Psychics will soon lead dogs to your body!

1963 Dodge Dart 270 convertible

You're right, it's "tube nut", not "tub nut". A tube nut is what holds the flare at the end of the tube to its seat. I see both tube nuts you need here, but you ought to be able to get 'em from a well-stocked auto parts jobber (the kind that sells real parts to grownups, not toys to kids) that has an extensive brake line supply range.

What are you doing for residual-pressure valves?

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

NAPA had them at one time. The last time I tried to get them, they were not available. I got a stock of them from the company in the link, Fed Hill.
If I remember correctly they are 1/2-20 and 9/16 -20 (not 9/16-18 ), with the unthreaded lead. Part numbers A15-3 and A16-3. Might want to get some Cunifer tubing if you order from them.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Thanks Dan Charlie.

Well Dan, I have researched the residual pressure situation immensely but have not made a final determination. ( !) Can you expound on the need for this for everyone's edification?
And what do you suggest?

Ok I confess! I thought cup expanders inside the wheel cylinders had pretty much made residual pressure valves obsolete. I know I need a proportioning valve for disc/drum but this is drum/drum so I didnt realize I needed any modifying aspects, might you please educate me?

John

_________________
Psychics will soon lead dogs to your body!

1963 Dodge Dart 270 convertible

So I found tube nuts locally here in a 5 pack. The are steel but since the MC fittings are inverted flare it doesn't look like the flat side of the tube nut will seal correctly, should I instead get the fittings in reverse flare?

BTW I love the help I get here, some things seem so simple but can end up as a can of worms so it is super to have the experience and know how at my fingertips, I have appreciated all the help yall have afforded me over the years!

Keep it up!

John

_________________
Psychics will soon lead dogs to your body!

1963 Dodge Dart 270 convertible

The residual pressure valve maintains slight pressure in the lines -- not enough to make the brakes drag, but enough to keep the shoes near the drums and prevent air entering the system via the wheel cylinders when the brakes aren't applied.
They keep air from getting in at the wheel cylinders, yeah, but they don't keep the shoes near the drums— see here are you sure you have them in your wheel cylinders? You had an RP valve in your single-pot master cylinder.

You can get the valve(s) you need in round or hex body.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Proper adjustment keeps the shoes near the drums.

Take a 15/16 wheel cylinder.....

It's area is .69 sqin. With a 10 psi valve, it will take 6.9 pounds of pressure to push it in (each cylinder).

You can do that with your thumb. The return springs are much stronger than your thumb.

So the shoe return springs will push against the wheel cylinders until stopped by the adjuster........


So you don't need the residual valve with the proper wheel cylinders.

_________________
Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Thanks for that information guys. Ill check into it further. I found brass fittings at napa here. Last trip to napa they did not have any fittings for me but lucked out this time.
Thanks all.

_________________
Psychics will soon lead dogs to your body!

1963 Dodge Dart 270 convertible

Yes, but not as consistently and effectively as when the correct valving is in place.

I long ago lost count of how many times I've heard or read "Halp, I put in a dual master cylinder and the system's bled and the brakes are adjusted but the pedal still seems soft/squishy!" followed by "Residual valves...? What's that?" or "Residual valve? No, I have recent wheel cylinders" eventually followed by "Huh, how about that. I guess I did need the residual valves after all."

(And before I lost count, I was including letters to car-help columns in the likes of Popular Science and Popular Mechanics in the 1970s that looked like "My '74 Dart has 4-wheel drum brakes. The car stops OK, but the brake pedal is squishy. The dealer says everything's fine. Help!")

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

I checked with the master cylinder manufacturer and the residual pressure valves are built into the MC.
John

_________________
Psychics will soon lead dogs to your body!

1963 Dodge Dart 270 convertible

Excellent -- that solves that problem.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.