TR2/3/3A Aftermarket brake and clutch master cylinders - black extension?

[71TR6]

I’m installing some aftermarket brake and clutch cylinders on my TR3A and I notice they came with these black extensions installed.
Does anyone know what these are for and why the cylinders come with them installed? Maybe a thread adapter???

 

[CJD]

It is a thread adapter. I know the TR2 came with one on the brakes from the factory. I would imagine those are because the MC threads are metric and they have to convert them to the Triumph BSF.

 

[mctriumph]

More than threads, it is the flare on the brake line that is getting adapted. Also it is advisable
to take the cylinder apart and check for a part that is often missing from these crappy AM
replacements. It is a tiny washer/spring that controls backflow.Take your old unit apart and re-use it
if it is missing.
Mad dog

 

[71TR6]

Thanks for the advice guys!
I'll have to take my old one apart and see where that washer/spring is located and confirm it's location.

 

[mctriumph]

It sits in end of the assy, in the cap that looks like a castle.Small waffle spring.
I dont know why the AM boys forgot it, but it makes the cylinder almost impossible
to bleed completely.
Mad dog

 

[TR4nut]

I just changed out a set on a friends 3A this past week. Look at the line going into the reservoir. If it is a bubble flare (convex, kind of mushroom shaped) take the adapter off. If your lines are a concave double flare, you need the adapter to seat properly.

 

[71TR6]

Randy- I dug out the old girling master cylinders to look for the adapters and there were none. I also noticed at the same time that they required bubble flares. Rather than use the old pipes, I made up some new ones with the double flare and plumbed up to the black adapters. The adapters don't have check valves in them so we'll see how the bleeding goes.
Ron