Matt,
I went through the same
problem, with the pump "blipping" about
every 4-5 seconds. In my case it only happened when the gear was
down.
I checked all the cylinders
first, believing that the dump valve could not leak in one direction
only.
The problem was the dump valve. In my installation it was very
easy to test by remove the dump valve and closing off the lines with some spare
fittings. This cured the "blipping". Lancair sells a valve rated at higher
pressure, but it is slightly larger and a lot heavier. I chose to replace mine
with the same valve, figuring I can replace it again in 8 years if need
be.
Bob Belshe
Moraga, CA
1992 Lancair
235/320 750hrs.
My hydraulic pump turns on when the gear is down at regular intervals
about every minute and it stays on for about 1 second.
It does not do this when the gear is up.
I don't think there is an internal leak in the cylinders.