PZL Compass

[Dave Springford]

I had similar problems with the PZL compass in my LS6. I refilled it
and then sealed it with epoxy, that didn't work for the reason
suggested abovein a previous message (and the reason listed below)

I learned from an older gentleman in Australia who sold me another PZL
compass that the reason these compasses leak is because people overfill
them.

In North America we are taught that air bubbles in compasses are bad
(indicates a leaking compass). This is because most of us use the
Airpath compass with a rubber diaphragm at the back of the unit to
react to the expanding fluid as the temperature increases. This allows
the Airpath to be filled with fluid.

The PZL compass does not have this feature, so there must be a large
airpocket in the instrument to allow for expansion. With the PZL
compasses, you cannot fill them more than about 2/3, otherwise the
fluid won't have room to expand and it will break the seal and leak.

So with the PZL compass an air bubble is good, Don't overfill!

Dave

[5Z]

Dave Springford wrote:
> So with the PZL compass an air bubble is good, Don't overfill!

Wow, I wish I knew that when I refilled it after repairing the melted
hole!

After it started leaking, I did notice that a fairly large bubble would
"hide" very nicely in the instrument. So, once I make the repair, I'll
put in just enough fluid so the bubble hides and see how it works.
Will report back after repairs have been made.

-Tom

[[email protected]]

Hi Dave - I didn't overfill mine, and they still leaked.
Where you able to finally seal the thing ?
If so, how ?
Thanks !
Best Regards, Dave "YO"

[Dave Springford]

Unfortunately I learned the hard way about over-filling so that
original compass continued to leak after I tried to seal it.

I purchased another (used) unit and put it in the glider and 3 years
later when I sold the glider, it was not leaking.

I no longer own the same glider, so I can not comment whether or not it
is still good 5 years later.

While the PZL compasses are much smaller, my personal preference is the
Airpath. It is much easier to maintain, and the overhaul kits are only
about $15.