Folks, I have a question: What would be the
symptoms of a master relay or pressure switch going bad with reference to
the hydraulic system?
The plane: IV-P, about 1150hrsTT, in the air over
13years now
The issue: I have had a couple of intermittent
(i.e., un-reproducible) issues related to 1) the flaps
having difficulty deploying against resistance at
anything over 140kts (used to be no sweat putting them down at 172kts);
and 2) a couple of times the amber hydraulic power pack “on” light stays
on constantly. In terms of #1, I replaced the
accumulator with a partially used one (Lancair was out of stock) and it
only partially helped the problem. I now have a new one from Lancair, and
plan on installing it this week. #2 has me perplexed, however. Just in the
last couple of weeks, I have had time when the amber light (hydraulic
pump) won’t go out. After a minute or so, I had to pull the 50amp circuit
breaker, and when I re-set it, the pump and light stayed off. Today,
however, there was a new twist—after landing, I put the
flap handle UP and nothing happened—the flaps didn’t move, and the pump
did not come on. I recycled the flap handle a couple of times and the pump
came on, flaps came up, and pump STAYED on. Pulled and reset 50 circuit
breaker, and pump went off but then right back on with the reset CB!. I
shut down completely, and then fired back up—all was well. Of note, there
has been no problem or lag with the gear rectract or deployment that I can tell.
So, I am wondering if there is more than just a
weak accumulator going on here. Does this story sound familiar to anyone?
Anything else I should look at while I am at it? Does it sound like a bad
master relay or pressure switch?
Thanks in advance for your thoughts/advice.