Hi Alain,
Reference your brakes not releasing:  And Service Bulletin 013-93.
The service bulletin indicates that you should comply with the
modification to the master cylinder if you have the copilot brakes
installed.  I do not so I ignored the SB.  However I had flat spot on the
right main after 50 hours and had a number of 'exciting' swerves on
landing that I previously blamed on poor pilot technique. Since 95% of my
landings are on turf so the tire life was increased and wear was not as
noticeable.

One day when backing the LCN2 into the hangar I noticed a considerable
resistance on the right side.  No amount of 'jiggling' on the master
cylinder would release the brake.  I had to open the bleeder valve to
release it.

I installed the tube that forces the check valve open per SB013-93 and
after 10 hours my landings have improved.  Perhaps they would have anyway
but I believe I had an intermittent sticking check valve.
My kit was delivered in 1988.  Newer Matco master cylinders may not need
this modification...

> I have to open the bleeder screw and let down few drop of hydraulic
fluid to
> free my brakes.Very interesting!Has anybody an opinion on this problem?

Earl E Schroeder Lancair N233EE Cessna N3595J
Evansville, Indiana