Pneumatics Question

Get rid of the 4-way connector. They are unreliable, sometimes
causing cross-talk between paths. For peace of mind, use separate
connectors.

Bob


- then traced my original TE troubles to a leak in the 4-way connector
at the panel. *Replaced the connector this year.

Get rid of the 4-way connector. *They are unreliable, sometimes
causing cross-talk between paths. *For peace of mind, use separate
connectors.


He mentioned it's a 5 way (although only 4 ports are currently being
used) in another post, which I mean to take is a Winter unit. I've
personally had good luck with those but I still prefer the positive
locking threaded compression connection of my 4 way PZL version. I've
had no leaks with either though, nor any crosstalk (ahem- well just be
sure you didn't x-thread the PZL unit back together on after you show
it off just before takeoff... heh.) Only problems I've heard of with
the quick connects are leaks when the stock O-rings are old/crusty,
which is an easy inspection/replacement (spend the extra $.12 on
Viton!). While crosstalk is possible on the PZL 4-way with it's
compression loaded seals, on the Winter 5-way there is no *real chance
of it as the o-rings form a male seal at least 1/4" into the female
sockets, effectively isolating the individual lines from each other in
case of seal failure, even with dual seal failure. Rubber is not
ageless... and again, silicone (spray, applied via cotton swab) is
your friend, same for the probe/socket...

It's also unlikely a probe connection problem since it is not a double-
probe and I feel safe to assume the probe gets taped at each assembly
of course. Borrowing a probe from another ship will help isolate any
problems with the probe itself it It winds up being suspect.

I may just have tunnelvision but really I think an old vario (with
aged internal seals...) that has pitot and TE seems more suspect of
crosstalk issues than a new Winter quick connect or probe performance
issues...

Slightly OT, I like to use these to seal pneumatic instrument hoses on
barbs:
http://www.jollygerman.com/products/goats/rings.shtml cheap, last
bout 5yrs and gives a uniform 360deg seal (UNlike zipties...) that is
easily future-accessed with no damage to hose/barb. Got idea from
Borgelt but it took me a while to figure out what these little green
rubber Cheerio things were *really* used for... OUCHY!!!

-Paul

It's also unlikely a probe connection problem since it is not a double-
probe and I feel safe to assume the probe gets taped at each assembly
of course. Borrowing a probe from another ship will help isolate any
problems with the probe itself it It winds up being suspect.

The Brunswick socket won't have any internal seals. Just one tube
inside another. Tape is unreliable. A short length of silicon tube
tightly fitted over the joint is better. If the tube can stay in situ
in the trailer then wire it or castrate it with a couple of Cheerios
and leave it well alone.

I may just have tunnelvision but really I think an old vario (with
aged internal seals...) that has pitot and TE seems more suspect of
crosstalk issues than a new Winter quick connect or probe performance
issues...

Seems the first port of call for an elimination exercise. I await some
more real data with fascination.

Whee ! Looks like I'm in for some fun this coming weekend, trying to
figure out what's leaking. I'll probably fly it in the daytime and
try to test it during the evening, or bring the panel home to test the
varios.

I think I was happier before I asked the question... oh well, test it
out and get it working nicely.

Thanks to all for the information and advice; I'll report back when I
figure it out.

-John