4 replies to this topic

[kyle9832]

Does anyone know the size of brake line i should be using on my mini and the size of the unions and threads and is it the same throughout the whole car? Cheers

Edited by kyle9832, 03 October 2015 - 08:18 PM.

[gazza82]

What year/model? Later ones used metric, early ones imperial ..

[kyle9832]

What year/model? Later ones used metric, early ones imperial ..

1978 austin:)

[Ethel]

Brake pipes are 3/16".

 

The unions do vary, you could find metric on any dual circuit car. It's best to be able to identify metric from imperial by sight, worth a google.

[Spider]

As Ethal has said, the pipe itself is 3/16". I was given some 5.0 mm pipe, near enough eh? Nope. I couldn't grip it in my tube Flairing Tool when selected to do the correct shape flares for imperial fittings.

 

All fittings, except as follows will be 3/8" UNF. The exceptions are;-

 

Most of the Tandem Master Cylinders, some (few) were Imperial

The Tandem Pressure Limiting Valve that is usually fitted in the Engine Compartment

If fitted, some of the Line Joiners (usually identifiable by having an Inverted Flare on the Original Tube)

 

These are M10 x 1.0 mm.

 

One other exception is one of the Ports on the Yellow Tag Master Cylinder, which was M12 x 1.0, however it's normally fitted up with a M12 - M10 reducing fitting.

 

If you run the Metro 4 Spot Calipers, these were also M10 x 1.0 mm.

 

<Edit:  If you are unsure of any particular thread, being Brakes, it's best you be sure.Buy just one each 3/8" UNF and M10 x 1.0 fittings to kick off with and use these to test. A 3/8" UNF Male fitting will go in to and do right up in an M10 x 1.0 mm Female fitting, however this could be dangerous. an M10 will only fit the M10 fittings and will not fit a 3/8" UNF fitting. 

 

The reason is when translated, 3.8" is closer to 9.5 mm, but if fitted and tighten in an M10 fitting, there is a risk it may fail and do so without warning. >

Edited by Moke Spider, 04 October 2015 - 04:33 AM.