Lulubelle, I don't have experience with plastic brake lines, but I have
encountered leaks in plastic plumbing lines to appliances because I left
too much plastic line beyond the ferrule. Tightening the nut doesn't
stop the leak. That may be your problem. The extra tubing prevents the
ferrule from seating all the way into the fitting, thus causing a leak.
You can see for yourself if it is seating properly into the fitting by
just pushing it in without putting the nut on the tubing so you can
observe what happens. If it doesn't seat all the way, that's the
problem. The cure is to cut the tubing a bit shorter, so that it only
sticks out ~1/8"
In general, if you do continue to use plastic line, my opinion is that
you should inspect it fairly often, at least during your annual
inspection, because I've read reports of older plastic brake lines
(installed years earlier) on experimental aircraft weakening and
expanding over time. It is certified in plumbing for use with water and
air, but I I don't know about long term contact with brake fluid that
operates under high pressure. Some brake fluids may have some chemicals
that aren't compatible for long term immersion in the tubing. Inspection
will make sure it is still in good shape. The pressure in brake lines is
far higher than what it would be in a water system.
On 7/20/2022 10:33 PM, Lulubelle Pitts via KRnet wrote:
It looks like this... In case you couldn't picture it... And the
reservoir is behind the seat. - Scott.
On Wed, Jul 20, 2022, 9:34 PM Lulubelle Pitts via KRnet
<krnet@list.krnet.org> wrote:
I'm having brake line leaks in the 1/8" plastic tubing, I think
because the ferrels won't seal the plastic ... any anyone else
deal with this? I'm thinking of replacing some of it with
aluminum tube at the reservoir but I'll have to connect to the
plastic down the line - I don't want to fish tube through to the
wheels because I'd have to cut or drill ... don't want to do that.
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