Saratoga Gear Retract Problem

[Yahoo! News]

During day one of my 2000 Saratoga's annual today my mechanic and I observed
the following problem. If anyone has some experience with this or they have
a mechanic that has experience with this I would love to hear about it:

Here is a description of what we are observing:

1) Gear retraction is initiated with handle being placed into the gear
up position

2) Nose gear and main gear unlock and start retraction

3) Gear Unsafe light illuminates simultaneously with gear unlocks

4) In about 1-2 seconds, nose gear completes retraction first (this is
normal as far as what I have observed in the past both on my plane on jacks
and on observing others from the ground departing from airports)

5) Main gear comes up part way but hesitates until nose gear completes
retraction - again I believe this is normal

6) Main gear almost completes retraction in about 2 seconds after nose
gear - a few inches from being completely retracted - this is where
something has changed.

7) Pump Motor shuts off for approximately ¼ second

8) Pump Motor starts again for approximately ¼ second and gear moves
up a little more (maybe ½ inch to 1 inch)

9) Pump Motor shuts off again and restarts again 3-5 times in the same
pattern of quick off and ons before gear is completely retracted and pump
motor remains off

10) Gear warning light extinguishes about the time or slightly before the
pump motor shuts off for the last time


This process is very repeatable. Only the number of quick off-on cycles of
the pump varies slightly. The pump almost always remains off for many
minutes once the gear is completely retracted. The gear was left in the up
position for at least 5+ minutes at one point and we did not observe any
restart of the pump. We did observe a quick on-off cycle of the pump
perhaps 5 seconds after retraction during just one of 15-20 retraction tests
performed, but again, normally the pump would shut off after the last cycle
and remain off for many minutes during our testing.


Everything seems normal compared to what I have observed when we did the
annuals before except for the pump cycling off and on near the end of the
main gear retraction cycle. We have studied the hydraulic and electrical
schematics for the system and looks like there is a pressure limit switch
that is responsible for stopping the pump motor when the pressure reaches
approximately 1800 psi. This should occur after all the gear is retracted
and against the physical stops. We are theorizing that this switch or the
contactor that it operates could be faulty and prematurely stopping the pump
prior to the gear being completely retracted. If the switch opened at a
lower pressure for instance or cycled between opened and closed in a lower
pressure range then it was supposed to we are thinking that the symptoms we
are seeing would result. According to the maintenance manual the switch is
supposed to close at 200 to 400 psi and open at 1800 +/- 100 psi. We have
looked all over for anything impeding the main gear retraction and were not
able to identify any hang-ups there. We have also verified that adequate
5606 is available in the reservoir of the pump.


Again if anyone has some insights on my gear retract symptoms I would sure
like to hear about it. If you believe our theory about the pressure limit
switch being bad is unlikely and that it would be wiser to go down another
path I would also like to hear about that too. My mechanic and I will be
all over this tomorrow so if you know anything about this post what you
know.

- George

[Michael Ware]

Well George, I don't know the first thing about your plane, but it seems a
straightforward way of troubleshooting the symptoms would be to place a
manually operated switch in the circuit in place of the hydraulic pressure
switch.
Another way to rule it in/out would be to put a test light on the load side
of the switch, see if it goes on/off when the pump does. Also, do you have a
way to monitor the hydraulic pressure while this is taking place? Perhaps
there is a partial blockage or other problem in the lines or in the
hydraulic actuators, causing the pressure to shoot up.

--
Hello, my name is Mike, and I am an airplane addict...

"Yahoo! News" > wrote in message
t...
> During day one of my 2000 Saratoga's annual today my mechanic and I
observed
> the following problem. If anyone has some experience with this or they
have
> a mechanic that has experience with this I would love to hear about it:
>
<snip>
>
> Again if anyone has some insights on my gear retract symptoms I would sure
> like to hear about it. If you believe our theory about the pressure limit
> switch being bad is unlikely and that it would be wiser to go down another
> path I would also like to hear about that too. My mechanic and I will be
> all over this tomorrow so if you know anything about this post what you
> know.
>
> - George
>
>

[Darrel Toepfer]

Michael Ware wrote:
> Well George, I don't know the first thing about your plane, but it seems a
> straightforward way of troubleshooting the symptoms would be to place a
> manually operated switch in the circuit in place of the hydraulic pressure
> switch.
> Another way to rule it in/out would be to put a test light on the load side
> of the switch, see if it goes on/off when the pump does. Also, do you have a
> way to monitor the hydraulic pressure while this is taking place? Perhaps
> there is a partial blockage or other problem in the lines or in the
> hydraulic actuators, causing the pressure to shoot up.

Ditto for me:

Or the pump is overloading if it has an internal thermal reset that
tripping as it gets loaded up...

[George Sconyers]

Thanks Mike,

We thought about replacing the switch with a manual switch to test with but
I did not want to stress the lines or acutators to 3000 psi where the
internal pump relief opens. The idea about placing a light across the
external pressure switch is a good one though. If the light comes on when
the gear stops going up for that 1/4 second we will then know it is due to
the pressure switch opening up and not some other electrical problem. I
guess if we determine the switch is opening up we will also have to try a
get a high pressure gauge and see if we can read it fast enough while the
cycling is going on to determine if the switch is opening up prematurly. I
received other documentation on the switch this morning that says that the
working range is only 200 - 400 psi (open at 1800 psi, close at 1400 -
1600 - much tighter than I thought the maintenance manual indicated closing
at 200 - 400 psi. This makes me even more learly of the switch.

- George
"Michael Ware" > wrote in message
m...
> Well George, I don't know the first thing about your plane, but it seems a
> straightforward way of troubleshooting the symptoms would be to place a
> manually operated switch in the circuit in place of the hydraulic pressure
> switch.
> Another way to rule it in/out would be to put a test light on the load
> side
> of the switch, see if it goes on/off when the pump does. Also, do you have
> a
> way to monitor the hydraulic pressure while this is taking place? Perhaps
> there is a partial blockage or other problem in the lines or in the
> hydraulic actuators, causing the pressure to shoot up.
>
> --
> Hello, my name is Mike, and I am an airplane addict...
>
> "Yahoo! News" > wrote in message
> t...
>> During day one of my 2000 Saratoga's annual today my mechanic and I
> observed
>> the following problem. If anyone has some experience with this or they
> have
>> a mechanic that has experience with this I would love to hear about it:
>>
> <snip>
>>
>> Again if anyone has some insights on my gear retract symptoms I would
>> sure
>> like to hear about it. If you believe our theory about the pressure
>> limit
>> switch being bad is unlikely and that it would be wiser to go down
>> another
>> path I would also like to hear about that too. My mechanic and I will be
>> all over this tomorrow so if you know anything about this post what you
>> know.
>>
>> - George
>>
>>
>
>

[Paul kgyy]

I had a similar problem with my Arrow and the solution was to rebuild
the hydraulic pump - check the actual pressure being generated. THe
high pressure switch might also be defective.

[The Visitor]

I have a seneca 3. My problem started out like that, easy to sort of fly
with. Then it got worse. Sometimes wouldn't at all retract, or just
partially then pump would go off.

We, flushed out and changed fluid, swaped up and down relays(they are
the same), measured pump pressure, changed pump/motor, gear was in no
way binding. The last thing checked was an over pressure limit switch
that was going faulty and shutting the pump off.

2000 Saratoga? Mmmmm, nice.

Our gear is probably similar in design?? Good Luck.

John

Yahoo! News wrote:
> During day one of my 2000 Saratoga's annual today my mechanic and I observed
> the following problem. If anyone has some experience with this or they have
> a mechanic that has experience with this I would love to hear about it:
>
> Here is a description of what we are observing:
>
> 1) Gear retraction is initiated with handle being placed into the gear
> up position
>
> 2) Nose gear and main gear unlock and start retraction
>
> 3) Gear Unsafe light illuminates simultaneously with gear unlocks
>
> 4) In about 1-2 seconds, nose gear completes retraction first (this is
> normal as far as what I have observed in the past both on my plane on jacks
> and on observing others from the ground departing from airports)
>
> 5) Main gear comes up part way but hesitates until nose gear completes
> retraction - again I believe this is normal
>
> 6) Main gear almost completes retraction in about 2 seconds after nose
> gear - a few inches from being completely retracted - this is where
> something has changed.
>
> 7) Pump Motor shuts off for approximately ¼ second
>
> 8) Pump Motor starts again for approximately ¼ second and gear moves
> up a little more (maybe ½ inch to 1 inch)
>
> 9) Pump Motor shuts off again and restarts again 3-5 times in the same
> pattern of quick off and ons before gear is completely retracted and pump
> motor remains off
>
> 10) Gear warning light extinguishes about the time or slightly before the
> pump motor shuts off for the last time
>
>
> This process is very repeatable. Only the number of quick off-on cycles of
> the pump varies slightly. The pump almost always remains off for many
> minutes once the gear is completely retracted. The gear was left in the up
> position for at least 5+ minutes at one point and we did not observe any
> restart of the pump. We did observe a quick on-off cycle of the pump
> perhaps 5 seconds after retraction during just one of 15-20 retraction tests
> performed, but again, normally the pump would shut off after the last cycle
> and remain off for many minutes during our testing.
>
>
> Everything seems normal compared to what I have observed when we did the
> annuals before except for the pump cycling off and on near the end of the
> main gear retraction cycle. We have studied the hydraulic and electrical
> schematics for the system and looks like there is a pressure limit switch
> that is responsible for stopping the pump motor when the pressure reaches
> approximately 1800 psi. This should occur after all the gear is retracted
> and against the physical stops. We are theorizing that this switch or the
> contactor that it operates could be faulty and prematurely stopping the pump
> prior to the gear being completely retracted. If the switch opened at a
> lower pressure for instance or cycled between opened and closed in a lower
> pressure range then it was supposed to we are thinking that the symptoms we
> are seeing would result. According to the maintenance manual the switch is
> supposed to close at 200 to 400 psi and open at 1800 +/- 100 psi. We have
> looked all over for anything impeding the main gear retraction and were not
> able to identify any hang-ups there. We have also verified that adequate
> 5606 is available in the reservoir of the pump.
>
>
> Again if anyone has some insights on my gear retract symptoms I would sure
> like to hear about it. If you believe our theory about the pressure limit
> switch being bad is unlikely and that it would be wiser to go down another
> path I would also like to hear about that too. My mechanic and I will be
> all over this tomorrow so if you know anything about this post what you
> know.
>
> - George
>
>

[George Sconyers]

Sure hope my problem is the same as yours. I just ordered the $672 switch
from Piper! Hopefully, my mechanic's discount he has setup with them will
bring the price down 30%. Do you remember what you payed for the pressure
limit switch (Piper part number 587-847)?

-George

"The Visitor" > wrote in message
...
>I have a seneca 3. My problem started out like that, easy to sort of fly
>with. Then it got worse. Sometimes wouldn't at all retract, or just
>partially then pump would go off.
>
> We, flushed out and changed fluid, swaped up and down relays(they are the
> same), measured pump pressure, changed pump/motor, gear was in no way
> binding. The last thing checked was an over pressure limit switch that was
> going faulty and shutting the pump off.
>
> 2000 Saratoga? Mmmmm, nice.
>
> Our gear is probably similar in design?? Good Luck.
>
> John
>
> Yahoo! News wrote:
>> During day one of my 2000 Saratoga's annual today my mechanic and I
>> observed the following problem. If anyone has some experience with this
>> or they have a mechanic that has experience with this I would love to
>> hear about it:
>>
>> Here is a description of what we are observing:
>>
>> 1) Gear retraction is initiated with handle being placed into the
>> gear up position
>>
>> 2) Nose gear and main gear unlock and start retraction
>>
>> 3) Gear Unsafe light illuminates simultaneously with gear unlocks
>>
>> 4) In about 1-2 seconds, nose gear completes retraction first (this
>> is normal as far as what I have observed in the past both on my plane on
>> jacks and on observing others from the ground departing from airports)
>>
>> 5) Main gear comes up part way but hesitates until nose gear
>> completes retraction - again I believe this is normal
>>
>> 6) Main gear almost completes retraction in about 2 seconds after
>> nose gear - a few inches from being completely retracted - this is where
>> something has changed.
>>
>> 7) Pump Motor shuts off for approximately ¼ second
>>
>> 8) Pump Motor starts again for approximately ¼ second and gear
>> moves up a little more (maybe ½ inch to 1 inch)
>>
>> 9) Pump Motor shuts off again and restarts again 3-5 times in the
>> same pattern of quick off and ons before gear is completely retracted and
>> pump motor remains off
>>
>> 10) Gear warning light extinguishes about the time or slightly before
>> the pump motor shuts off for the last time
>>
>>
>> This process is very repeatable. Only the number of quick off-on cycles
>> of the pump varies slightly. The pump almost always remains off for many
>> minutes once the gear is completely retracted. The gear was left in the
>> up position for at least 5+ minutes at one point and we did not observe
>> any restart of the pump. We did observe a quick on-off cycle of the pump
>> perhaps 5 seconds after retraction during just one of 15-20 retraction
>> tests performed, but again, normally the pump would shut off after the
>> last cycle and remain off for many minutes during our testing.
>>
>>
>> Everything seems normal compared to what I have observed when we did the
>> annuals before except for the pump cycling off and on near the end of the
>> main gear retraction cycle. We have studied the hydraulic and electrical
>> schematics for the system and looks like there is a pressure limit switch
>> that is responsible for stopping the pump motor when the pressure reaches
>> approximately 1800 psi. This should occur after all the gear is retracted
>> and against the physical stops. We are theorizing that this switch or
>> the contactor that it operates could be faulty and prematurely stopping
>> the pump prior to the gear being completely retracted. If the switch
>> opened at a lower pressure for instance or cycled between opened and
>> closed in a lower pressure range then it was supposed to we are thinking
>> that the symptoms we are seeing would result. According to the
>> maintenance manual the switch is supposed to close at 200 to 400 psi and
>> open at 1800 +/- 100 psi. We have looked all over for anything impeding
>> the main gear retraction and were not able to identify any hang-ups
>> there. We have also verified that adequate 5606 is available in the
>> reservoir of the pump.
>>
>>
>> Again if anyone has some insights on my gear retract symptoms I would
>> sure like to hear about it. If you believe our theory about the pressure
>> limit switch being bad is unlikely and that it would be wiser to go down
>> another path I would also like to hear about that too. My mechanic and I
>> will be all over this tomorrow so if you know anything about this post
>> what you know.
>>
>> - George
>>
>>
>

[john smith]

> I have a seneca 3. My problem started out like that, easy to sort of fly
> with. Then it got worse. Sometimes wouldn't at all retract, or just
> partially then pump would go off.
> We, flushed out and changed fluid, swaped up and down relays(they are
> the same), measured pump pressure, changed pump/motor, gear was in no
> way binding. The last thing checked was an over pressure limit switch
> that was going faulty and shutting the pump off.
> 2000 Saratoga? Mmmmm, nice.
> Our gear is probably similar in design?? Good Luck.

John, which engine on the Seneca drives the hydraulic pump?

[[email protected]]

On Mon, 28 Nov 2005 22:19:54 GMT, john smith > wrote:

>> I have a seneca 3. My problem started out like that, easy to sort of fly
>> with. Then it got worse. Sometimes wouldn't at all retract, or just
>> partially then pump would go off.
>> We, flushed out and changed fluid, swaped up and down relays(they are
>> the same), measured pump pressure, changed pump/motor, gear was in no
>> way binding. The last thing checked was an over pressure limit switch
>> that was going faulty and shutting the pump off.
>> 2000 Saratoga? Mmmmm, nice.
>> Our gear is probably similar in design?? Good Luck.
>
>John, which engine on the Seneca drives the hydraulic pump?

The electric one bolted to the top of the powerpack-think Meyer snow
plow.

TC

[john smith]

In article >,
wrote:

> On Mon, 28 Nov 2005 22:19:54 GMT, john smith > wrote:
>
> >> I have a seneca 3. My problem started out like that, easy to sort of fly
> >> with. Then it got worse. Sometimes wouldn't at all retract, or just
> >> partially then pump would go off.
> >> We, flushed out and changed fluid, swaped up and down relays(they are
> >> the same), measured pump pressure, changed pump/motor, gear was in no
> >> way binding. The last thing checked was an over pressure limit switch
> >> that was going faulty and shutting the pump off.
> >> 2000 Saratoga? Mmmmm, nice.
> >> Our gear is probably similar in design?? Good Luck.
> >
> >John, which engine on the Seneca drives the hydraulic pump?

> The electric one bolted to the top of the powerpack-think Meyer snow
> plow.

(Sound of Homer Simpson "dope slap")
Can you tell I'm not a multi-pilot? :-))

[Jim Burns]

"john smith" > wrote
> > >John, which engine on the Seneca drives the hydraulic pump?
>
> > The electric one bolted to the top of the powerpack-think Meyer snow
> > plow.
>
> (Sound of Homer Simpson "dope slap")
> Can you tell I'm not a multi-pilot? :-))

Don't feel bad, it's the left engine on our Aztec, no electric hyd pump.

Now... along those lines... what would cause a sudden "over flow puddle"
from our Aztec's hyd system? Plane's annual was this summer, hyd system
topped off with fluid, we've flown it about 40 hours since then. Saturday,
the engines were due for fresh oil and filters so I took her out for a short
joy ride to warm everything up. Changed the oil and filters but didn't have
a chance to pull it back out and do a run up to check for leaks. So last
night I go up to the hanger to do that and I notice a puddle of hyd fluid
directly below the overflow tube near the rear of the nose gear wheel well.

The drop hanging from the overflow tube confirmed where it was coming from,
nothing else wet or washed off, but why? why after 40 hours of flying and
probably a dozen gear/flap extensions and retractions would it decide to
overflow any excess fluid at this time??

I was able to add about 6-8 oz of fluid to the system to top it off. Ran
the flaps up and down, no leaks noticed anywhere, no additional overflow out
the overflow tube. System fill tube stayed full.

Any ideas??? TC what ya think??

Thanks
Jim

[[email protected]]

I think that raising and lowering a rubber hose to blindly
service/verify the proper level in a power pack reservoir is really
goofy. Not sure if that's how yours works or not, but on the newer
models the hose was clipped to the side of the nose.

In the past, whenever I serviced an Aztruck pack, it would typically
vent some on it's first or second (or third) flight, but it never
appeared to be very much.

I guess I would keep an eye on it to make sure that it isn't still
venting, or if it does drip a little more, make sure that it stops
after it decides it's at the proper level.

TC

[The Visitor]

I do remember it is real costly. My mechanic took out mine and cleaned
it up inside and now it works just fine. So you should look at that
possibility. Lots of things are not repairable, but really are. I do
recall all that troubleshooting cost me close to 3k$.

John





George Sconyers wrote:
> Sure hope my problem is the same as yours. I just ordered the $672 switch
> from Piper! Hopefully, my mechanic's discount he has setup with them will
> bring the price down 30%. Do you remember what you payed for the pressure
> limit switch (Piper part number 587-847)?
>
> -George
>
> "The Visitor" > wrote in message
> ...
>
>>I have a seneca 3. My problem started out like that, easy to sort of fly
>>with. Then it got worse. Sometimes wouldn't at all retract, or just
>>partially then pump would go off.
>>
>>We, flushed out and changed fluid, swaped up and down relays(they are the
>>same), measured pump pressure, changed pump/motor, gear was in no way
>>binding. The last thing checked was an over pressure limit switch that was
>>going faulty and shutting the pump off.
>>
>>2000 Saratoga? Mmmmm, nice.
>>
>>Our gear is probably similar in design?? Good Luck.
>>
>>John
>>
>>Yahoo! News wrote:
>>
>>>During day one of my 2000 Saratoga's annual today my mechanic and I
>>>observed the following problem. If anyone has some experience with this
>>>or they have a mechanic that has experience with this I would love to
>>>hear about it:
>>>
>>>Here is a description of what we are observing:
>>>
>>>1) Gear retraction is initiated with handle being placed into the
>>>gear up position
>>>
>>>2) Nose gear and main gear unlock and start retraction
>>>
>>>3) Gear Unsafe light illuminates simultaneously with gear unlocks
>>>
>>>4) In about 1-2 seconds, nose gear completes retraction first (this
>>>is normal as far as what I have observed in the past both on my plane on
>>>jacks and on observing others from the ground departing from airports)
>>>
>>>5) Main gear comes up part way but hesitates until nose gear
>>>completes retraction - again I believe this is normal
>>>
>>>6) Main gear almost completes retraction in about 2 seconds after
>>>nose gear - a few inches from being completely retracted - this is where
>>>something has changed.
>>>
>>>7) Pump Motor shuts off for approximately ¼ second
>>>
>>>8) Pump Motor starts again for approximately ¼ second and gear
>>>moves up a little more (maybe ½ inch to 1 inch)
>>>
>>>9) Pump Motor shuts off again and restarts again 3-5 times in the
>>>same pattern of quick off and ons before gear is completely retracted and
>>>pump motor remains off
>>>
>>>10) Gear warning light extinguishes about the time or slightly before
>>>the pump motor shuts off for the last time
>>>
>>>
>>>This process is very repeatable. Only the number of quick off-on cycles
>>>of the pump varies slightly. The pump almost always remains off for many
>>>minutes once the gear is completely retracted. The gear was left in the
>>>up position for at least 5+ minutes at one point and we did not observe
>>>any restart of the pump. We did observe a quick on-off cycle of the pump
>>>perhaps 5 seconds after retraction during just one of 15-20 retraction
>>>tests performed, but again, normally the pump would shut off after the
>>>last cycle and remain off for many minutes during our testing.
>>>
>>>
>>>Everything seems normal compared to what I have observed when we did the
>>>annuals before except for the pump cycling off and on near the end of the
>>>main gear retraction cycle. We have studied the hydraulic and electrical
>>>schematics for the system and looks like there is a pressure limit switch
>>>that is responsible for stopping the pump motor when the pressure reaches
>>>approximately 1800 psi. This should occur after all the gear is retracted
>>>and against the physical stops. We are theorizing that this switch or
>>>the contactor that it operates could be faulty and prematurely stopping
>>>the pump prior to the gear being completely retracted. If the switch
>>>opened at a lower pressure for instance or cycled between opened and
>>>closed in a lower pressure range then it was supposed to we are thinking
>>>that the symptoms we are seeing would result. According to the
>>>maintenance manual the switch is supposed to close at 200 to 400 psi and
>>>open at 1800 +/- 100 psi. We have looked all over for anything impeding
>>>the main gear retraction and were not able to identify any hang-ups
>>>there. We have also verified that adequate 5606 is available in the
>>>reservoir of the pump.
>>>
>>>
>>>Again if anyone has some insights on my gear retract symptoms I would
>>>sure like to hear about it. If you believe our theory about the pressure
>>>limit switch being bad is unlikely and that it would be wiser to go down
>>>another path I would also like to hear about that too. My mechanic and I
>>>will be all over this tomorrow so if you know anything about this post
>>>what you know.
>>>
>>>- George
>>>
>>>
>>
>
>

[Jim Burns]

> I think that raising and lowering a rubber hose to blindly
> service/verify the proper level in a power pack reservoir is really
> goofy. Not sure if that's how yours works or not, but on the newer
> models the hose was clipped to the side of the nose.

Goofy. Ditto. Raise it, fill it, lower it, check it, raise it, add some
more, lower it. Clip it back in place. Goofy.

>
> In the past, whenever I serviced an Aztruck pack, it would typically
> vent some on it's first or second (or third) flight, but it never
> appeared to be very much.

The puddle seemed to be about two tablespoons full I would guess. Created a
stain about 6" dia.

> I guess I would keep an eye on it to make sure that it isn't still
> venting, or if it does drip a little more, make sure that it stops
> after it decides it's at the proper level.

Present course of action. Plane's leaving for a 4 day trip this weekend.
It's topped off now and we'll see what it looks like when it comes back.

Thanks as always.

Jim

[tom418]

I paid $550 for a replacement switch for my Seneca1 five years ago. Glad I
had it replaced then. Same part (mfg. by Consolidated Controls)

"George Sconyers" > wrote in message
...
> Sure hope my problem is the same as yours. I just ordered the $672 switch
> from Piper! Hopefully, my mechanic's discount he has setup with them will
> bring the price down 30%. Do you remember what you payed for the pressure
> limit switch (Piper part number 587-847)?
>
> -George
>
> "The Visitor" > wrote in message
> ...
> >I have a seneca 3. My problem started out like that, easy to sort of fly
> >with. Then it got worse. Sometimes wouldn't at all retract, or just
> >partially then pump would go off.
> >
> > We, flushed out and changed fluid, swaped up and down relays(they are
the
> > same), measured pump pressure, changed pump/motor, gear was in no way
> > binding. The last thing checked was an over pressure limit switch that
was
> > going faulty and shutting the pump off.
> >
> > 2000 Saratoga? Mmmmm, nice.
> >
> > Our gear is probably similar in design?? Good Luck.
> >
> > John
> >
> > Yahoo! News wrote:
> >> During day one of my 2000 Saratoga's annual today my mechanic and I
> >> observed the following problem. If anyone has some experience with
this
> >> or they have a mechanic that has experience with this I would love to
> >> hear about it:
> >>
> >> Here is a description of what we are observing:
> >>
> >> 1) Gear retraction is initiated with handle being placed into the
> >> gear up position
> >>
> >> 2) Nose gear and main gear unlock and start retraction
> >>
> >> 3) Gear Unsafe light illuminates simultaneously with gear unlocks
> >>
> >> 4) In about 1-2 seconds, nose gear completes retraction first
(this
> >> is normal as far as what I have observed in the past both on my plane
on
> >> jacks and on observing others from the ground departing from airports)
> >>
> >> 5) Main gear comes up part way but hesitates until nose gear
> >> completes retraction - again I believe this is normal
> >>
> >> 6) Main gear almost completes retraction in about 2 seconds after
> >> nose gear - a few inches from being completely retracted - this is
where
> >> something has changed.
> >>
> >> 7) Pump Motor shuts off for approximately ¼ second
> >>
> >> 8) Pump Motor starts again for approximately ¼ second and gear
> >> moves up a little more (maybe ½ inch to 1 inch)
> >>
> >> 9) Pump Motor shuts off again and restarts again 3-5 times in the
> >> same pattern of quick off and ons before gear is completely retracted
and
> >> pump motor remains off
> >>
> >> 10) Gear warning light extinguishes about the time or slightly before
> >> the pump motor shuts off for the last time
> >>
> >>
> >> This process is very repeatable. Only the number of quick off-on
cycles
> >> of the pump varies slightly. The pump almost always remains off for
many
> >> minutes once the gear is completely retracted. The gear was left in
the
> >> up position for at least 5+ minutes at one point and we did not observe
> >> any restart of the pump. We did observe a quick on-off cycle of the
pump
> >> perhaps 5 seconds after retraction during just one of 15-20 retraction
> >> tests performed, but again, normally the pump would shut off after the
> >> last cycle and remain off for many minutes during our testing.
> >>
> >>
> >> Everything seems normal compared to what I have observed when we did
the
> >> annuals before except for the pump cycling off and on near the end of
the
> >> main gear retraction cycle. We have studied the hydraulic and
electrical
> >> schematics for the system and looks like there is a pressure limit
switch
> >> that is responsible for stopping the pump motor when the pressure
reaches
> >> approximately 1800 psi. This should occur after all the gear is
retracted
> >> and against the physical stops. We are theorizing that this switch or
> >> the contactor that it operates could be faulty and prematurely stopping
> >> the pump prior to the gear being completely retracted. If the switch
> >> opened at a lower pressure for instance or cycled between opened and
> >> closed in a lower pressure range then it was supposed to we are
thinking
> >> that the symptoms we are seeing would result. According to the
> >> maintenance manual the switch is supposed to close at 200 to 400 psi
and
> >> open at 1800 +/- 100 psi. We have looked all over for anything
impeding
> >> the main gear retraction and were not able to identify any hang-ups
> >> there. We have also verified that adequate 5606 is available in the
> >> reservoir of the pump.
> >>
> >>
> >> Again if anyone has some insights on my gear retract symptoms I would
> >> sure like to hear about it. If you believe our theory about the
pressure
> >> limit switch being bad is unlikely and that it would be wiser to go
down
> >> another path I would also like to hear about that too. My mechanic and
I
> >> will be all over this tomorrow so if you know anything about this post
> >> what you know.
> >>
> >> - George
> >>
> >>
> >
>
>

[George Sconyers]

The problem was indeed the pressure sensor switch. Gear retract time is now
3-4 seconds total and smooth.

"Yahoo! News" > wrote in message
t...
> During day one of my 2000 Saratoga's annual today my mechanic and I
> observed the following problem. If anyone has some experience with this
> or they have a mechanic that has experience with this I would love to hear
> about it:
>
> Here is a description of what we are observing:
>
> 1) Gear retraction is initiated with handle being placed into the
> gear up position
>
> 2) Nose gear and main gear unlock and start retraction
>
> 3) Gear Unsafe light illuminates simultaneously with gear unlocks
>
> 4) In about 1-2 seconds, nose gear completes retraction first (this
> is normal as far as what I have observed in the past both on my plane on
> jacks and on observing others from the ground departing from airports)
>
> 5) Main gear comes up part way but hesitates until nose gear
> completes retraction - again I believe this is normal
>
> 6) Main gear almost completes retraction in about 2 seconds after
> nose gear - a few inches from being completely retracted - this is where
> something has changed.
>
> 7) Pump Motor shuts off for approximately ¼ second
>
> 8) Pump Motor starts again for approximately ¼ second and gear moves
> up a little more (maybe ½ inch to 1 inch)
>
> 9) Pump Motor shuts off again and restarts again 3-5 times in the
> same pattern of quick off and ons before gear is completely retracted and
> pump motor remains off
>
> 10) Gear warning light extinguishes about the time or slightly before
> the pump motor shuts off for the last time
>
>
> This process is very repeatable. Only the number of quick off-on cycles
> of the pump varies slightly. The pump almost always remains off for many
> minutes once the gear is completely retracted. The gear was left in the
> up position for at least 5+ minutes at one point and we did not observe
> any restart of the pump. We did observe a quick on-off cycle of the pump
> perhaps 5 seconds after retraction during just one of 15-20 retraction
> tests performed, but again, normally the pump would shut off after the
> last cycle and remain off for many minutes during our testing.
>
>
> Everything seems normal compared to what I have observed when we did the
> annuals before except for the pump cycling off and on near the end of the
> main gear retraction cycle. We have studied the hydraulic and electrical
> schematics for the system and looks like there is a pressure limit switch
> that is responsible for stopping the pump motor when the pressure reaches
> approximately 1800 psi. This should occur after all the gear is retracted
> and against the physical stops. We are theorizing that this switch or the
> contactor that it operates could be faulty and prematurely stopping the
> pump prior to the gear being completely retracted. If the switch opened
> at a lower pressure for instance or cycled between opened and closed in a
> lower pressure range then it was supposed to we are thinking that the
> symptoms we are seeing would result. According to the maintenance manual
> the switch is supposed to close at 200 to 400 psi and open at 1800 +/- 100
> psi. We have looked all over for anything impeding the main gear
> retraction and were not able to identify any hang-ups there. We have also
> verified that adequate 5606 is available in the reservoir of the pump.
>
>
> Again if anyone has some insights on my gear retract symptoms I would sure
> like to hear about it. If you believe our theory about the pressure limit
> switch being bad is unlikely and that it would be wiser to go down another
> path I would also like to hear about that too. My mechanic and I will be
> all over this tomorrow so if you know anything about this post what you
> know.
>
> - George
>
>

[[email protected]]

On Tue, 29 Nov 2005 13:16:25 -0600, "Jim Burns"
> wrote:

>Goofy. Ditto. Raise it, fill it, lower it, check it, raise it, add some
>more, lower it. Clip it back in place. Goofy.

The only one I've come across that is goofier was the old Navajos. The
powerpack fill pipe was hooked to the side of the brake reservoir. You
over-filled the brake reservoir until it ran into the power pack.

Another goofy thing about this system (which carried through on the
newer models) was the screw-down Thermos-type combination
stopper/dipstick. Was mounted under a little flapper door on the top
of the nose.

The "rubber" on the stopper was semi-incompatible with 5606, and
usually leaked. Depending on the amount of precipitation present,
water would run under the door, around the stopper and into the
reservoir.

This wasn't typically a problem until winter, when the globs of water
would freeze in the lines, either rendering some/all of the brake
system inop, or trapping pressure in the lines-locking some/all of the
brakes. Had most of the line guys trained to crack the bleeders and
shove the !@$% thing into the hangar to thaw out when it happened when
I wasn't around.

>> In the past, whenever I serviced an Aztruck pack, it would typically
>> vent some on it's first or second (or third) flight, but it never
>> appeared to be very much.
>
>The puddle seemed to be about two tablespoons full I would guess. Created a
>stain about 6" dia.

Sounds familiar.

>> I guess I would keep an eye on it to make sure that it isn't still
>> venting, or if it does drip a little more, make sure that it stops
>> after it decides it's at the proper level.
>
>Present course of action. Plane's leaving for a 4 day trip this weekend.
>It's topped off now and we'll see what it looks like when it comes back.

Good deal.

>Thanks as always.

My pleasure.

TC