In Richard Johnson's flight test of the original Discus he replaces the
mylar seals with internal fabric seals & gets a noticeable improvement in
performance.

The mylar on my Discus CS is 20years old & starting to lift in places, so I
will need to replace it.

Has anyone out there done the internal seal mod?
Did you think there was any advantage
Can I have both internal & mylar seals?

The pushrod holes for Aileron & Airbrake are sealed with rubber bellows.
These are also 20 yrs old.
Anyone know of a way to test whether these are perished, no longer
sealing?

Many thanks

PF