Front Brake pipes

Technical questions and answers
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5988
Posts: 692
Joined: Fri Mar 13, 2009 8:57 pm
Location: Lincolnshire

Front Brake pipes

Post by 5988 »

Are the brakes pipes between the front cylinders the same each side?
my parts book gives one part number, which ive now got two of (pre-bent) one fits perfectly the other is no where near.
i cant see how they could be the same form the way there bent , (pic in parts book looks to be an un-bent pipe) so maybe the same then you bend them, these being bent are different? havent got the old ones to check as they were rather mangled getting them off

second queston - anyone know what the thread on late (1980 onwards) S3 brake pipes is, ive got new flexibles and cant work out what it is (definatly not metric, Unf or unc, or whitworth) and none of the supplies recognise the part no
i havent got the old ifttings as the ones of the old pipes are different (im thinking that although my S1 is registered in 81 maybe it was built a bit before and actualy had the earlier pipes before the changeover...not that its to much of a problem is it now has new brake pipes, just need the nuts for these)
map1275
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Joined: Mon Jul 21, 2008 2:48 am
Location: Brisbane, Australia

Post by map1275 »

You are using the same name for two different things.

From memory the brake pipes for each front hub are handed. Fittings at the wheels are imperial.

Brake hoses for this period are metric. Therefore fittings that attach to the hoses and some other components are metric.
5988
Posts: 692
Joined: Fri Mar 13, 2009 8:57 pm
Location: Lincolnshire

Post by 5988 »

thanks for the info on the pipes
just to confirm the ones im talking about are the ones against the back plate between the front cylinders - parts book gives 2 of whatever the number is
but they seem handed -
the fittings in the cylinders and pieces etc are imperial (have all those as there the same as series 2's)
i had assumed the flexi pipes would be metric at that age....but couldnt find a tap or die in my sets that fit them...back to looking tomorrow then
map1275
Posts: 1077
Joined: Mon Jul 21, 2008 2:48 am
Location: Brisbane, Australia

Post by map1275 »

Front pipe, cylinder to cylinder is listed as NRC5347, pre bent and ambidextrous. I don't have an early parts list to see what the previous number was.

Brake hose identification is covered in just about every BL workshop manual and Haynes from the early 1970's.

From memory, the typical thread to replace 3/8 UNF is 10 x 1.
5988
Posts: 692
Joined: Fri Mar 13, 2009 8:57 pm
Location: Lincolnshire

Post by 5988 »

map1275 wrote:Front pipe, cylinder to cylinder is listed as NRC5347, pre bent and ambidextrous. I don't have an early parts list to see what the previous number was.
thats what id got from the parts book....just part desnt fit, bck to the upplier then
the typical thread to replace 3/8 UNF is 10 x 1.
probably why i cant find it i only have the corse metric taps and dies
5988
Posts: 692
Joined: Fri Mar 13, 2009 8:57 pm
Location: Lincolnshire

Post by 5988 »

you remembered correctly thay are M10x1

gave up on the pre-bent front pipe and made up a new one (well i didnt as i kept making a mess of the bends) so now sorted
pre-bent one definatly doesnt fit, maybe bent wrong
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