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Regarding the recently reported problems I've had with my gear pump
"pulsing", I am pelased to announce that by following the advice gotten here
to check the individual cylinders before doing anything else drastic (like
pulling the hydro pump and sending it off to Oildyne), I have identified the
right main cylinder as the culprit.

I now know which unit is leaking internally and have ordered the required
materials from Lancair to rebuild the cylinder (actually, I'll probably do
all three since failure in the others is probably not far behind). However,
here's another question - to those of you who have R&R'd their cylinders: Is
it absolutely necessary to remove the body of the cylinder from the
airplane? Or is it possible to do the necessary work as long as the
actuating rod and piston can be removed while leaving the cylinder body in
place? (This looks to be entirely possible, by the way).

The reason I'm asking is that it looks to be a real nightmare to get at the
nut on the bolt holding the cylinder body in the mounting block. I don't
know about later designs but on my early 235, that area was closed in with
an angled piece (as an afterthought by the factory) that basically closes
the shear web about 6 inches outboard of the anchor bolt. As instructed,
there is an access hole in the web for a wrench, but it's going to be very
difficult to get in there with all the other stuff (like push-rod idler,
etc.) in the way.

Getting the nut off the bolt and out of the wing is probably doable (with a
lot of newly invented words, I'm sure) but getting it back in when it comes
to reinstalling the bolt looks to be nigh on to impossible as it was
originally installed when the gear well was much less populated. Any
thoughts on the problem?

Any good words on the subject would be appreciated.

Dan Schaefer


[Dan... on later models the inboard bolts that retain the cylinders are
used in the "pin" mode, IOW there is no nut on them.   Instead the bolt
is slid home and a keeper is mounted to the phenolic block that runs from
the bolt inboard to the closeout rib.  Tightening the nut that holds the
keeper in place is a simple matter, as it is completely accessible.  You
might want to retrofit this to your airplane to simplify future
removals of the cylinders.  I'll send you a scan of the keeper from the
320 manual so you can see just how it works.        <Marv>       ]

LML website:   http://www.olsusa.com/Users/Mkaye/maillist.html
Builders' Bookstore:   http://www.buildersbooks.com/lancair

Please send your photos and drawings to marvkaye@olsusa.com.