Replacing rear brake lines (metal pipes).

[Andy335Touring]

Compair them to the original pipe flares ?

[jmpwr]

The 3/16 will work. The original is din 4.75mm. If you look at the origanal pipe the area that the tube nut touches is slightly flatter than the SAE 3/16. I have used both types on BMW's without any problems.

[Brianmoooore]

If you look into the fitting that the pipe is to be attached to, it's fairly obvious as to whether you need a single or a double flare on the pipe end.

[tomstickland]

Well, it's all finished and no leaks.
However, the original factory formed pipe ends are far more substantial that anything a pipe flaring kit could make.

[Dave_M3]

Going tackling this job next week

Have the BMW lines, new tee piece, goodridge braided hoses all ready

[old_skool]

Dameon. This is a job I'm going to do over the winter. Figure I can take my time and "get it really right" so to speak So you recommend the original BMW pipe but whats the best way to bend it. I've seem to remember seeing miniature pipe bending kits (small versions of the plubmers ones). What did you use mate?

Trevor, the plumbers mini pipe benders are no good, they will not offer a tight enough bending radii and they are not the right size. They are 6, 8, & 10mm. The pipe we use for E30's is 4.76mm - 3/16".

I found the best method for bending kunifer or factory pipe is a deep 1/2" socket of varying sizes. With care the pipe can be manipulated around the socket to a very tight bend and exactly replicate the factory pipes. If done gently you will not collapse the pipe. It really isn't that difficult. I usually use different size sockets to achieve different bends (as above) and put the socket is a vice to hold it.

If you get the chance then take a look at the rear 'over axle' pipes I made for Barry's car, they are exact repicas to the OEM pipes.

That's just my method. As Brian says, Kunifer is very good but if your after OEM or concours look then OEM steel sections are the way to go. If you are afraid of bending the pre supplied sections wrongly tehn buy an extra front to rear (long) pipe and you can make up your own by cutting and re flaring it. I find that the OEM steel pipe flares better than Kunifer too.

Good luck!

[tomstickland]

I found that Kunifer pipe bends very easily using your fingers to spread the load. I haven't bothered exactly replicating the OEM pipes.

[tomstickland]

Also changed the subframe bushes: