Making front brake hose from Venhill parts

I need a new front brake hose for my 72 Combat. It has a Stock master cylinder (soon to be upgraded to AN's 13mm item) and Grimeca caliper, the bars are 'semi western' 06.1046. can anyone enlighten me on what the threads are at the caliper and the master cylinder.
Thanks

The master cylinder is 3/8" x 24 UNF.

The Grimeca caliper should be M10 x 1.00mm.

L.A.B. said:

The master cylinder is 3/8" x 24 UNF.

The Grimeca caliper should be M10 x 1.00mm.

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Thanks LAB, just what I needed

I assume the Master cylinder connection is like This

Tom P said:

I assume the Master cylinder connection is like This

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You could use that fitting although it will probably need a copper sealing washer.

Or you can use a straight or angled banjo and 3/8" UNF banjo bolt.

If a screw fitting is used at both ends then it makes it more difficult to fit without one being a swivel and adaptor fitting as it involves screwing either the caliper or master cylinder onto the brake line.

Looking at the andover site the connection to the master cylinder does not seem to use a copper washer. how does the standard part seal, is the thread tapered? or does it have a convex or concave tip

Tom P said:

Looking at the andover site the connection to the master cylinder does not seem to use a copper washer.

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Not shown doesn't necessarily mean it doesn't need one.

Tom P said:

how does the standard part seal, is the thread tapered?

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With a (copper) washer as it's a parallel thread.

Tom P said:

or does it have a convex or concave tip

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There is a concave seating but it's deeper than the length of the standard threaded end fitting and as can be seen from the pictures does not have a convex seating at the master cylinder end.

L.A.B. said:

Not shown doesn't necessarily mean it doesn't need one.



With a (copper) washer as it's a parallel thread.



There is a concave seating but it's deeper than the length of the standard threaded end fitting and as can be seen from the pictures does not have a convex seating at the master cylinder end.

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Does it amuse you to set us mere mortals straight? You have a slightly humorous streak in you that you may or may not know. My dad is like that, unintentionally funny. Anyways, thanks for the laughs.

When I fitted the braided brake lines to my bike, I just took a caliper and the master cylinder to the local hot-rod shop and bought the bits. In Australia, most of the kids play with Holden cars which are General Motors products. Most of the brake bits are probably threaded UNF. Most aircraft use UNF fasteners, and most are made in America. With Italian brake parts, you can get both fine and coarse metric threads. I think the Japanese use coarse metric. But I have a rear master cylinder off a Ducati which uses fine metric.

Larry S said:

You have a slightly humorous streak in you that you may or may not know.

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I can't think what you mean Larry? You must have got me mixed up with somebody else?
The length of the original hose end fitting thread is approximately .408" and the AN fitting looks a similar length...


...The depth of the master cylinder thread (also brake switch thread) is approximately .575" to the tapered seating...


...therefore the standard fitting (and brake light switch) requires a sealing washer. The standard convex braided end fitting would also be too short to reach the taper although the longer threaded "Bulkhead" fitting should.

This is the adaptor and swivel fitting I use. The line can then be positioned free of kinks or stress before the fitting is tightened.




(Edit: For our Australian and NZ members: note that brake line compression fittings are not legal for road use in those countries.)