Master Cylinder steel inlet tubes

[J.Peter]

Thanks for all the ideas on various posts on this forum.
I recently replaced a Master Cylinder on my 1970 911 E. As all of you know - The only tough part of the job is those two inlet pipes that go into the top. I unsuccessfully tried all of the suggested tricks to install those pipes easily.
I finally removed the MC reservoir and the pipes from my car and even on the bench I could not get those steel flared ends into the rubber grommets. Those flares are just too large in diameter to fit into those new grommets.
I reduced the outside diameter of those flares until the pieces could be assembled without undo force. The attached photo shows one flare reduced and one the original size before I filed it down as well. I did not remove the flares I only reduced them substantially.
They function perfectly on the vehicle. During normal operation the actual pressure in that line is only a few inches of head so they will not be blown off while braking. My concern was during pressure bleeding so I bench tested it and they held at 30 psi as I had expected they would.
It appears that the only real reason those flares as so large is to irritate anyone who tries to reassemble them and they do that nicely. They do not contribute to the sealing of the lines in any way.
My recommendation to anyone doing this MC refit job is to remove the pipes from the vehicle – it is only two hose clamps – and then file down those flares. It is easiest to remove the pipes from inside the car while you are working down by the brake pedal.

[Shoepop]

Personally never had a problem.