2 replies to this topic

[1314cc]

I'm hopefully replacing front disc brake hoses soon plus the front subframe copper brake pipe. Any advice on how tight I should do the bolt at the flared end? I'm guessing not mega tight?!!

[Compdoc]

The amount of torque is a bit difficult to explain in writing, but all soft metal pipe connections like brass and copper rely on the the mating surfaces of the flange crushing slightly together to form a good seal. If you use a spanner no longer than say 6 inches, you should be able to feel the nut go tight then feel the tiny amount to crush the flange. You'll soon know if its too loose when you can't bleed the brakes or if the thread strips... its too tight. Good luck.

[tiger99]

For a start you should be using cupro-nickel, not copper, whose poor fatigue properties make it totally unsuitable for brake systems. It has no approval for that use, whereas cupro-nickel is made and approved to the correct specifications.

Having said that, hand tight with an average length open ended spanner is about the correct torque. Afterwards, hold the pedal down very hard for a couple of minutes, then check for the slightest sign of leakage. There probably will be none, but if so, wipe very clean, nip up a bit more, and repeat the test.

Edited by tiger99, 01 July 2016 - 07:58 PM.