Wonderful. I did the EXACT same thing in May. Rebuilt all
three gear cylinders due to 1 slight leak. Result. Massive hydraulic leak
problems that persist to this day. I’ve now replaced two entire cylinders and
may need to replace the third…
I’m at a loss, frustrated, and in desperate need of a shop in
the southeast that will help me TROUBLEshoot the problem (as opposed to
continually replacing cylinders).
Matt
From: Lancair Mailing
List [mailto:lml@lancaironline.net] On Behalf Of kneaded pleasures
Sent: Monday, October 29, 2007 1:59 PM
To: lml@lancaironline.net
Subject: [LML] Gear cylinder hydraulic gaskets
Matt Reeves wrote back in late August:
"I have a Lancair 320. I just found a leak coming
out of the end of the left main hydraulic cyl on the high side. It is not
coming out of the fittings, it's actually coming out of the end where the stop
jam is. It's just a small leak but I rebuilt this
cylinder once already cause I thought there was an internal leak so my opinion
is this is a defective cylinder."
Matt: The problem is probably not with the cylinder -
or your workmanship! It is probably due to a wrong piston gasket
being included in the cylinder rebuild kit. I had an identical
problem with one cylinder and chose to rebuild all three gear cylinders at the
same time. After ordering rebuild kits (just gaskets in the kits) I
installed the new gaskets and two leaked after rebuild. I removed
them and critically reexamined the supplied materials and my
workmanship. (Meanwhile, I reordered from Lancair two more gasket
kits.) I then noted that the newly-supplied leaking gaskets differed
from both the very old rotted gaskets that I had originally removed
and also differed from the two newest gaskets that I had just
received from Kit Components. (The gasket that I am targeting
here is the gasket that surrounds the piston as it extends/withdraws from
the cylinder.)
The differences in these gaskets are easy too see and
measure. The new and correct gaskets are the same as the very-old,
original and now rotted gaskets. They have an O-ring embedded
inside of the plasticized gasket. {I "dis-sected" (the word is
not "di-sected") an old gasket to observe this.} Writing
on the good/proper/desired gasket is illegible to me. However, writing is
very clear on the IMPROPER gasket and it reads, "USA
.375 MP I K3E.1". Further,
the good/non-leaking gasket stands noticeably higher on a flat surface -
perhaps four or five mils higher than the poor/leaking gasket (probably
important at 2000 psi).
Summarizing, don't throw away your leaking cylinders before
you first check to ensure that the correct replacement gasket is
installed. Look for the tell-tail embedded "O ring" that is
prominently visible on the top of the correct gasket.
Greg Nelson