MatraSport Forum

Does the nylon fluid pipe simply pull out of the cylinder? I hesitate to pull too hard in case I break something!
regards
Ron

Hi,
You can just pull out the nylon fluid pipe, it is difficult to get out, but when you have loosened the nut, the pipe can be pulled out. I have done it a few times!
Hans

Thanks Hans

The reason that getting the pipe out is difficult is that the rubber that has sealed it in all these years (?) has become locked in to the thread and pipe.  Putting it back to seal can be a problem if not done correctly.

I have explained this more than once in the club magazine, but briefly, the hard fluid pipe will have become narrowed where it is sealed in, and this must be removed so that you have the full diameter again, plus a new rubber seal, to seal it again when you put it back.  This applies to either the slave or master cylinder end.  If you do not do this, it will leak either fluid or allow air in and become impossible to bleed properly.

The flare nut presses on a washer which squashes the new rubber seal to secure and seal the plastic pipe in to the slave or master cylinder.  So make sure you have the washer as well as the new rubber seal.  Also make sure you clean out all the old rubber seal bits first as it will break up once the pipe is removed.

Roy

It looks like this.
Be aware that there is a small metal pipe in the end of the plastic so it is not skweezed when you tighten the nut.
(https://lh3.googleusercontent.com/-l3gMlAvU8Mw/VT-A_99BIWI/AAAAAAAAGR0/GC0RQhSI-H4/s800/akopp.JPG)
pipe and nut
(https://lh3.googleusercontent.com/-6Ck9R7bMV8g/VT-HrMyH1gI/AAAAAAAAGSE/CIFQ4GxdqB0/s621/bus%2520%2528Custom%2529.jpg)

As I've just had a request for some help concerning the clutch hydraulics, it is worth bringing this thread up to date for those that may have not come across it before.

The Murena uses fairly conventional clutch master and slave cylinders, but it does NOT connect them together with a metal pipe, flared ends and flare nuts.  A plastic pipe is used and this presented the engineers with a problem - how do you seal a plastic pipe into the master and slave cylinders which were meant to take a metal pipe with flared ends?

What they came up with was this.  First the plastic pipe ends had metal inserts pushed in to stop the pipe collapsing inwards under pressure (see photo below).  Then the flared nut was put on the pipe followed by a washer and then a small rubber tube which would do the sealing (see Herman's photo in the previous posting).  You push the pipe fully in to the cylinder, and whilst holding it there, you tighten down the flare nut.  That has the effect of pushing the washer against the rubber tube and squashing it such that it presses hard into the thread of the cylinder on the outside diameter and it presses hard against the plastic pipe on its inside diameter.  This jams and locks everything solid.

Because the pipe is jammed in very tight, when you wish to remove the plastic pipe many years later to do a repair, you can unscrew the flare nut easily, but the rubber will still be jammed in tight and it will take some effort to pull the end of the pipe out.  When you do get it out, the rubber will have been destroyed and you must make sure you get all the bits out of the cylinder before any reassembly.  After some years bolted tight, the plastic pipe will also have deformed near the end, and become permanently narrower.  You must cut off this narrowed section, after first removing the metal support pin inserted there.  If you don't cut off the narrow section, then replace the pipe insert, the new tube seal will not be able to seal the pipe in the cylinder.

Roy