Dual Master Cylinder Conversion

[ew1usnr]

Hello, Roger.

You talked about lubricating pipe threads. Would dipping the brake switch threads in brake fluid work?

I made another revision yesterday. I went to NAPA and bought two "Brake Fit Tube Nuts" (#641-3296 and #641-3322) for 69 cents each and then went to "Just Brakes" and had them attached.
brake lines.JPG

The mechanic used a tube cutter to cut the ends off the brake lines. He re-flared the lines with a "bubble flare" and said that this was the flare that my 8-inch brake lines had come with. I made a brief look at the internet about the subject and saw the comment: "Automotive brake lines are always a 45 degree double flare or a DIN (bubble) flare." Here are my bubble flares:
fittings.JPG

Here is an internet photo comparing the bubble and double flares. I need to read more about the difference between the two:
bubble flair and double flair.png

Here are what they look like attached. This eliminated two adapters. If the custom flare fittings leak, I can always get a couple of new brake lines and try the adapters.
on master cylinder.JPG

[Luva65wagon]

I've never seen bubble flares on a car before, so I'd need to study those too. Our cars used 45 double flares.

As for brake fluid as a lube, as long as when you tighten it, and all is said and done, if you don't have any hint of a leak, you're probably OK.

Happy new year - there.

[redfalken]

I've never dealt with bubble flairs but they came into standard in the mid-80s. Maybe even in metric systems. Do they use the same fittings as the double flair?

[ew1usnr]

A NAPA shop near my house has a machine shop. I will visit there tomorrow and see if they can put a "45 degree double flare" on the ends of the brake lines.

Description read on internet: "Inverted Flare or 45 is on all standard automotive applications, and cars and trucks from the 30's to mid 80's have inverted flare fittings at all the connections. Inverted flare is a single nut that uses a 45 degree double flare. This flare is lapped over so the tube is double thickness at the end."

See: http://inlinetube.com/install%20instructions/Instruct%20tube%20flaring%2045.htm

[redfalken]

For about $50 (on the cheap end) you can get a double flaring tool kit and pipe cutter. I've always flared brake lines myself and think it's really easy. After watching some YouTube videos and practicing a few times, it's not difficult to get the hang of. And you'll have the tool when you need it again. And you will probably need it again down the road.

Old lines tend to seize to the nut and will twist as you try to remove them. The wheel cylinders are notorious for this and if they are original, you should put them on your list of things to replace. That's what blew out on Jeff's wagon. Even with a dual master cylinder, the rest of the system should be tended to. Check the rubber hoses going to the front wheels and rear distribution block on the differential. If they're getting dry and cracking...replace.

[BadBird]

If you decide to buy a double flaring set, I would advise you spend a few extra bucks and buy a good quality brand. Search the internet on what is the best for the buck. I bought a cheaper version and the flares were bad and leaked. Bought a better set and they work great. I agree with Kenny that it is a good purchase and the tubing cutter along with a decent tubing bender will get used again and again. Larry

[ew1usnr]

Here is my updated configuration. The brake lines attach directly to the master cylinder and the only pipe thread is for the hydraulic brake light switch.
master cylinder.JPG

The owner of the Meineke car care center near my house used a hand-held hydraulic press to make the flare in my brake lines, and he did it for free! He's a good guy.

Tube Nuts and Flares.JPG

Here is my final parts list for the conversion:
From NAPA auto parts:
Part Number M2036 New 1967 Ford Mustang Master Cylinder, $63.49
Part Number SL134 Stoplight Switch, 1/8-NPT, 27 threads per inch, $8.99
Part Number 641-3296, Brake Fit Tube Nut, $0.69
Part Number 641-3322, Brake Fit Tube Nut, $0.69

From O’Reilly auto parts.
Part Number PA-308, 8” x 3/16” brake line with a fitting on each end (2 X $4.99), $8.98
Part Number 130333, 3/16” Union Tee (3/16" fitting has 3/8" - 24 threads), $5.99

From e-bay:
Part Number: ALL50137, AllStar Performance 3/16" Inverted Female Brass Tee Brass with a 1/8” NPT gauge port, $8.49 + free postage
Grand Total: $88.83.

Trivia: I used a bathroom scale and found that the 1967 Mustang master cylinder weighs 5.2 lbs.

The clerk told me that it was actually less expensive for me to buy a new rather than a reconditioned master cylinder because I did not have an old master cylinder to turn it for the core fee. NAPA Master Cylinder for 1967 Mustang with manual brakes: http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Brake-Master-Cylinder-New/_/R-NMAM2036_0358750724

“Beginning in 1967, Ford went to the federally mandated dual braking system, which provides braking pressure should the front or rear system fail. This is a dual reservoir master cylinder, with separate reservoirs feeding master cylinder bores positioned in tandem. Stepping on the brake pedal pressurizes separate front and rear brake systems.”
See: http://www.mustangmonthly.com/techar.../photo_03.html