MC feeder brake line replacement?
 

Just wanted to verify something with the group.

As part of my 930 brake upgrade on my 72T, I've changed my master cylinder to 23mm. The problem is the change in location of the MC feeder line inlet location and the hard (plastic/polyvinyl?) lines used to feed brake fluid from the reservoir to the mc. The angle of the bend needed to clear the steering rack and enter the footwell does not allow the inlet pipe and rubber pipe seal to seat correctly.

I used a 45 degree bend (provided by ate) and used more flexible clear vinyl tubing to connect the new inlet connection to the a section of the old polyvinyl tubing cutoff at a convenient location. I used hose clamps at both ends to seal the connections tightly. I don't think that I have to worry about pressure as it is primarily gravity fed and "pulled" in by the MC action.

Will I have a problem with the vinyl tubing related to brake fluid incompatibility causing deterioration or contamination of the brake fluid?

Anybody been there done that?

Rick

Depends on the tube material I made a similar extension on mine, no problem. You will also need to relocate the stoplight switch(at least I did) and a longer rod(included in the kit if you bought an up grade kit)

Bill,
Thanks for the reply. I guess the replacement tubing I used might work.

The stop light switch looks to be okay on my 72. It is activated when the pressure applied by a flat washer at the top of the mc shaft is released during pedal application.

The "kit" did not include a longer rod and I will have to fabricate a longer one. I noticed that there is a 1/4 or 1/2 inch of extra length I need to add when I finished the install. I'll probably just use a threaded rod or bolt cut to the appropriate length. The old shaft ended cone-shaped with a 6-8mm ball at the end. I don't think I need to replicate that due to my non-Porsche master cylinder replacement. I'm assuming that it mated to a cup in the old mc and spread the load. Do I need to create a ball-end on my "replacement" shaft to diffuse the pressure on the mc plunger? It doesn't sound like a bad idea.

Rick


Rick

Just for future reference, the reservoir tube is available from Ate in a 5 m roll Ate#02.358-0005.5

What's tube are currently available?

Do we have a new record for the oldest thread revival?

Bill is still active so we may get an answer too!