Brake connector sizing...AN???

[GrahamPaige29]

Hi guys. Went to get some brake hoses for my '29 Graham at the parts store and the salesman simply gave up after looking at the thread size. Does this cylinder have an unusual thread size?  Is this an "AN" fitting?  You can see the diameter in the pics and at the bottom of the hole is a taper.  Are there hoses available with this connector or do you have to use an adapter?    There is a number on the cylinders C 67697. Thanks. 

[PFitz]

Are you certain the brake hose attaches directly to that wheel cylinder hole ? 

 

With Wagner systems of your car's age the brake hose end fittings are a much larger thread. They often attached the brake hose to a brass "banjo  fitting" (pix attached). Then used a  hollow, cross-drilled "banjo bolt" through the fitting and into the wheel cylinder - with a copper washer under the bolt head and a smaller diameter washer between the banjo and the cylinder.

 

I doubt you'll ever find hoses for a car that early at an autoparts store. But they are still being made. You can get new manufacture hoses, with the correct size Wagner Lockheed end fittings, from Roberts Motor Parts .  http://www.robertsmotorparts.com/store/

 

BTW, I do not recommend using NOS brake hoses. They all-too-often swell shut with modern brake fluids and the wheel cylinders will stay under pressure, dragging the shoes, after you let the pedal up.

 

And, Classic and Exotic has repros of many of the Wagner Lockheed hose connections (adapters) to the brake lines and cylinders. http://www.classicandexotic.com/store/c-14-fittings-adapters-washers-clips.aspx

 

 

More words of caution. NEVER use refrigeration/plumbing soft copper tubing for brake lines. It is not strong enough. Only use Kunifer-10 copper/nickel alloy brake tubing. It's the only original look brake tubing that is DOT approved.   

 

Plus, the original brake line brass flair fittings get old and weakened with the constant outward pressure of their tapered seat. If they are starting to turn pink, the zinc in the brass alloy that helps give the brass strength, is gone, don't use them.  I have found quite a few brass brake line flair fittings over the years that were cracked and leaking. And I know of one bad roll-over accident when a master cylinder feed line flair fitting cracked while the car was coming down a steep hill. 

 

Hearing rumors a few years ago of autoparts store Chinese made flair nuts being of questionable strength,  I tracked down a USA company that still makes the long-taper brass flair nuts exactly to original  SAE specs for the early Wagner Lockheed systems.   25 foot rolls of new, high-strength copper lines (1/4 inch and 5/16 inch OD), and new  USA made, SAE spec, long-taper brass flair nuts to fit that tubing, are now sold as a kit through the H. H. Franklin Club.  http://www.franklincar.org/

 

Paul

Edited August 26, 2017 by PFitz (see edit history)

[joe_padavano]

2 hours ago, GrahamPaige29 said:

Hi guys. Went to get some brake hoses for my '29 Graham at the parts store and the salesman simply gave up after looking at the thread size. Does this cylinder have an unusual thread size?  Is this an "AN" fitting?  You can see the diameter in the pics and at the bottom of the hole is a taper.  Are there hoses available with this connector or do you have to use an adapter?    There is a number on the cylinders C 67697. Thanks. 

 

 

 

You are measuring the minor diameter of the female threads, which frankly is a pretty useless number.  A 1/2-20 thread would have a minor diameter of between 0.446 and 0.457.  Of course, that assumes this hole is a standard UNC or UNF thread.  Have you tried a 1/2-20 bolt in the hole?

[cahartley]

Tap size for 1/2"-20 threads is .453 so I think the above suggestion is a very good one.......  

[GrahamPaige29]

Ahh the banjo connectors are very interesting. I'll look into ordering the once I determine the exact thread size.  As for the back axle I will need some kind if adapter to go from each cylinder to 1/4" line to a "tee" connector. Thanks Paul. 

 

[Frank DuVal]

Did you check Hagen's Auto Parts? A great resource for Graham parts. Type Graham into the search box on the main page. They list 1929 brake rubber lines for many models.  I see one model uses 11/16" threads.

 

All the Grahams I've seen (OK that's a joke, I only have worked on mine!) used hoses that screwed directly in the wheel cylinders on front. The rears of course use one hose to the rear axle assembly and steel lines to the wheel cylinders.

 

I use Cunifer for all my brake and fuel lines now. I am tired of making steel lines for the SECOND time. My daily drivers get the salt treatment in the winter around here. Eats steel lines quickly nowadays. Also, Summit Racing carries stainless steel brake line guard, that spring looking armor on some lines from the factory. Makes a really good looking line. Also they have SS flare nuts.

[PFitz]

1 hour ago, GrahamPaige29 said:

Ahh the banjo connectors are very interesting. I'll look into ordering the once I determine the exact thread size.  As for the back axle I will need some kind if adapter to go from each cylinder to 1/4" line to a "tee" connector. Thanks Paul. 

 

 

 On that page I linked to at Classic and Exotic - for the rear axles, they have a brass tee fitting often found  on the rear axle (BRK-0012) with Wagner Lockheed systems. Plus the brake line to hose fitting that usually is mounted though a steel bracket on the chassis (BRK-007 ). Both fit the end thread of the Robert's brake hose.

 

Here's a picture of a typical, original Wagner Lockheed hose tee fitting on a rear axle. The other end of the hose attaches to the fitting mounted in a bracket on the chassis (off the top of the picture).   The copper line on each side of the tee fitting go to the left and right wheel cylinder's banjo fittings of the rear axle ( as seen in the third picture of my last post).

 

Paul

Edited August 27, 2017 by PFitz (see edit history)

[JV Puleo]

The AN thread system was developed during WWII. The letter stand tor Army/Navy. The idea was to get a system that both services could use. Up until then, they had used different systems which wasn't a problem until the huge expansion of materiel during wartime. So... no, they can't be AN fittings because those hadn't been invented in 1929.

[GrahamPaige29]

Ok I determined the cylinders do have 1/2-20 threading. I already have what I believe are three 11/16" fitting hoses. I will need to acquire two BRK 0013 adapters for the front,  three BRK 007 to covert the hose ends to 1/4" line, one BRK 0012 tee and some kind of adapters to change the rear cylinders to df fittings. Expensive!  

[PFitz]

I didn't see the 1/2 - 20 thread banjo bolts on Classic and Exotic's website, but you could ask if they have them.  If not, and you can't find any,  those hollow bolts would not be difficult for a machine shop to make.

 

FWIW, the Wagner Lockheed part number for that banjo bolt is FC-673.

 

The two, 1/16 inch thick copper washers to seal the bolt head to the banjo, and the banjo to the wheel cylinder, are still available from NAPA but you'll have to go by size, they can't convert the FC-602 and FC-603 part numbers anymore.  

 

Paul 

Edited August 28, 2017 by PFitz (see edit history)

[GrahamPaige29]

Hi guys.  I did find this one adapter fitting in my "junk" box.  It converts the 11/16" brake hose to fit in the cylinder.  I believe this is the same as part BRK 0013.  I'm wondering if I can dispense with the banjo connectors at least in the front and go this way.  Frank thought that's how Graham did it.  I think using two BRK 0007s on the other ends of the front hoses should do.  Now just figure out what I need for the back.

 

Oh and thank you guys so much for helping out.  I know I'm a rank amateur but I'm having so much fun (and frustration in equal measures) putting my car together.  My wife would like to start seeing me again at some point but she'll be happy riding around in the car when it's done.

[jpage]

Wagner used to make some 1/2-20 thd. hoses, No. F80022 (1/2-20 f x 1/2-20 m) 21 3/8 in.long, no. F80029 (1/2-20 f x 1/2-20 m) 27 3/8 in. long. the female end has the horseshoe clip for a bracket. These may still be available through from NAPA or a good brake shop. I could find no listing for casting numbers in my old Wagner catalog.

[GrahamPaige29]

Hey guys, the parts for the rear axle are VERY expensive if you try to keep it authentic with the 11/16" hose tee fitting.  I'm thinking of using a more modern hose just in the back where it can't be seen.  Does this diagram look ok to you?  I'm essentially trying to avoid the expensive "vintage" parts and go with standard size 1/4" line in the back.  So adapters at both cylinders to convert the 1/2" to standard 1/4" line.  Both lines into a "tee".  Then an adapter on the third fitting of the t to allow a modern hose to be used.  I can get all these parts online for a fraction of the cost of the 11/16" tee alone.