Braided brake hose for '75 MKIII

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Neilgb

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Hello to the Norton Knowledgeable,

I have bought a '75 Commando MKIII with standard USA bars and am working through it making it roadworthy. This is my first Norton, my first British motorcycle and my first vintage motorcycle. (I Have owned many different modern motorcycles for decades). First challenge is the braking. I have searched Access Norton but have not found a clear answer to the questions I have.

1) Does any one make braided hoses for the MKIII? It has a short hose (~10.5") from the master cylinder to a short bundy pipe and then another hose from the bundy to the caliper. I have not been able to find anyone that carries these.
2) What are the fitting threads and lengths if I have to order custom parts (I do not want to disassemble to brake to measure them up before ordering them).
3) A single braided hose from Master Cylinder to caliper has been suggested by a vendor - does anyone have experience with this set up and how did you retain the hose in place?
4) If I can't get braided hoses I will just get OEM style hoses from Andover Norton.

I have overhauled the front caliper with new pads and installed an Andover Norton 13mm Master Cylinder. Great improvement in feel and braking.

Thank you for any help you can provide.
 
Back in the early eighties i replaced both front rubber pipes with aeroquip braided stainless ones on my first Mk3. Made to the same length as the original ones. I found the bottom hose (from bottom yoke to slider bracket) bent the hose in a way that i was not happy with, especially when the forks were compressed, as under braking. It would have been better to fit a longer bottom hose and put a loop in it. This could be the reason why you find only single hoses from M/C to caliper from the usual suppliers. That and the cost, The braided SS hose is not too costly, its the fittings and especially stainless fittings that put the price up.
I use the OEM hoses from AN
 
Neilgb said:
1) Does any one make braided hoses for the MKIII? It has a short hose (~10.5") from the master cylinder to a short bundy pipe and then another hose from the bundy to the caliper. I have not been able to find anyone that carries these.
Click to expand...
I would have thought just about anyone making brake lines in the US could.
As I live in the UK then I can only suggest Venhill USA but I expect our American members can suggest others.

Venhill | Control Cables and Braided Brake Lines for Motorcycles, Quad Bikes, Cars & Karts | Venhill USA

Venhill Engineering Ltd - UK manufacturer of braided brake lines and control cables for motorcycles and industry since 1970
www.venhillusa.com www.venhillusa.com

Neilgb said:
2) What are the fitting threads and lengths if I have to order custom parts (I do not want to disassemble to brake to measure them up before ordering them).
Click to expand...

The fittings are 3/8" UNF with a 90 degree tapered seating.

Neilgb said:
3) A single braided hose from Master Cylinder to caliper has been suggested by a vendor - does anyone have experience with this set up and how did you retain the hose in place?
Click to expand...

If you choose a single line then I suggest it is made with an adaptor and swivel fitting at the upper end.
Braided brake hose for '75 MKIII
 
Neilgb said:
Neilgb said:
3) A single braided hose from Master Cylinder to caliper has been suggested by a vendor - does anyone have experience with this set up and how did you retain the hose in place?
Click to expand...
Click to expand...
As LAB suggested a swivel fitting at the upper end is good, but a swivel fitting at both ends of the hose is better, otherwise you are rotating the caliper to screw it onto the pipe fitting. If you do go down the route of stainless braided hose you will need to make sure that the hose braid doesn't come into contact with anything at all. It acts like a very good saw and will wear through anything it is touching. Wrapping the hose with spiral cable sleeveing or similar works to prevent this. Some of the propriety hose kits come with the hose already sleeved.
 
Neilgb said:
Hello to the Norton Knowledgeable,

I have bought a '75 Commando MKIII with standard USA bars and am working through it making it roadworthy. This is my first Norton, my first British motorcycle and my first vintage motorcycle. (I Have owned many different modern motorcycles for decades). First challenge is the braking. I have searched Access Norton but have not found a clear answer to the questions I have.

1) Does any one make braided hoses for the MKIII? It has a short hose (~10.5") from the master cylinder to a short bundy pipe and then another hose from the bundy to the caliper. I have not been able to find anyone that carries these.
2) What are the fitting threads and lengths if I have to order custom parts (I do not want to disassemble to brake to measure them up before ordering them).
3) A single braided hose from Master Cylinder to caliper has been suggested by a vendor - does anyone have experience with this set up and how did you retain the hose in place?
4) If I can't get braided hoses I will just get OEM style hoses from Andover Norton.

I have overhauled the front caliper with new pads and installed an Andover Norton 13mm Master Cylinder. Great improvement in feel and braking.

Thank you for any help you can provide.
Click to expand...
I have both AN hoses in stock (06-6243 bottom, 06-6237 top). I generally use custom DOT-approved hoses. They are clear plastic covered braided stainless. They do not have the protector that 06-6243 has.

I love the MK3 and Trident setup - I would never switch to a single hose! If you really want one, I can have it made but need an exact measurement shoulder to shoulder. I already know what ends are needed.

I have them made. If interested PM me.
 
Were the genuine brake line fittings made to AN dash 3 (or AN-3) spec? The smallest hose and fittings size today appears to be AN-4. AN meaning "Army Navy" (corrected), not Andover Norton!!

Addition: Genuine hydraulic hoses had an ID = 1/8", which corresponds with AN-3, so it appears all fittings adheres to the AN-3 standard.

- Knut
 
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mdt-son said:
AN meaning "Air (Force) Navy"
Click to expand...

Do you mean Army-Navy (AN)?

What are AN Fittings and Adapters?

AN fittings and adapters are threads used in plumbing and hydraulic systems. Click here to learn more about AN fittings and adapters.
www.titanfittings.com

Army-Navy fittings have a 37-degree flare. British motorcycles were 45(?) degree which I believe is SAE or DOT standard not AN.
 
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Sorry, I meant Army-Navy. Corrected above. Thanks for the clarification on flare size, which is an important distinction.

So I will have to specify 1/8" BSPP SAE fittings for my custom brake hose. (1/8 BSPP has a major diameter of 0.383" and 28 TPI).

I wonder how many of our esteemed members have verified the flare angle of their non-standard caliper(s) and master cylinders?

- Knut
 
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Just a bit of info from an A&P mechanic: AN fittings indeed have a 37 degree flare as do JIC fittings - Joint Industry Conference. The thread form is also the same. Something I discovered when making test equipment years ago and for caps and plugs for disconnected lines. One can't use JIC on aircraft of course but for protecting/testing it was a lot cheaper than expensive AN.

I have stock hoses on my MKIII front brake but with a 10" disc and 13mm MC and the feel is fine. Tough to bleed though!
 
At the end of the days use turn the bars to the left and ziptie the front brake lever back to the handgrip. This will keep the feel solid for the next ride out. I use one of the reusable zipties.
 
I have never known what the standard is for brake fittings. When I lived in Melbourne, one of the racing car guys had a business supplying hot-rod shops. He sold me the bits for my brake lines on my Seeley. I just cut the lines to length and assembled the system, without any drama. I recognised there must have been a standard for the fittings. The stainless steel bits were probably made in America, my brake calipers and master cylinder are probably British. It might have something to do with 'hands across the ocean' ? In the defence industries a lot of stuff was standardised during WW2.
 

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