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Hydraulic Flaps Question


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4 hours ago, Bob_Belville said:

That would be Cole. And yes they should catch it and service as necessary but it would not hurt to point it out to Joey assuming you have input. If Joey is working for the seller you might want to be sure that he brings it up. 

Already talked to Joey.  He’s jiggy with a tear-out of the interior for the 208AD. He’d be working for me, and I’ll give him a list of other stuff I’m concerned about ( though he sounds like he’s already on top of it) If prepurchase goes well I’m gonna see about adding shoulder harnesses while it’s there as well as a couple of other small items like the whelen strobes are wired to the beacon. I’d like them separate if not too big a deal.

Edited by MIR2018
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7 minutes ago, MIR2018 said:

got any idea what they cost?

The minor change kit ( what they attach too ) was like 20 bucks. You have 2 options on the belts "fixed" and "inertia real". The Fixed harnees you have to loosen the shoulder strap to be able to move around, in rough air the Inertia Real could pin you in the seat, I went the fixed route and they were $700ish for the front seats, but they didn't match in color or buckle with the rear belts so the wife had me replace those as well (another 350). I ordered everything thru LASAR. The left side clamp for the shoulder strap is a little tricky to get in place (tight quarters), the outboard rear belts are tricky as well, there again just not much room. 

Side Note: mine have the "Lift" type buckles which can and have been undone if you have manual gear, if I was to do it over I would go with the Push Button buckles

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4 minutes ago, RLCarter said:

Side Note: mine have the "Lift" type buckles which can and have been undone if you have manual gear, if I was to do it over I would go with the Push Button buckles

I went with amsafe push button inertial reals.  They work great and don't have to undo it to switch tanks.

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6 minutes ago, Jim Peace said:

I went with amsafe push button inertial reals.  They work great and don't have to undo it to switch tanks.

How are the inertia reals in rough air? I don't mind the fixed strap and even tight I can reach most things needed, but I have undone the right sweaters belt more than once, funny thing is they generally don't realize it

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4 hours ago, RLCarter said:

How are the inertia reals in rough air? I don't mind the fixed strap and even tight I can reach most things needed, but I have undone the right sweaters belt more than once, funny thing is they generally don't realize it

They are fine.  I never noticed a problem.  Feels just like when I am at work.  They are on and I don't have to think about it.  I had them installed by an old school mechanic at Van nuys.  Came out great.  I did not do any for the back seat.  I hardly have anyone there and it seems like a non issue.

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I went with the mounting kit from Spruce; $20, IIRC.  Somehow, I ended up with an extra set.  If you want to pay postage you can have it.  PM me.

I went with fixed from Hooker ($420), and have zero complaints.  I like being able to cinch them up real tight for take-off and landing; then slack in flight.  When I need to switch tanks I just slip my shoulder under the belt, and slip it back when I'm done.  I've had annoying experiences with inertia lock retractors in various cars over the years; lock-up, won't retract/tension, and locked where I couldn't pull the belt out!  Had to take the damn thing apart...total PIA!

Didn't want to repeat any of that with the plane!

Installed them myself (NEVER again!) and had my A&P sign off the install.  All-in, a little over $500.

If you can find an A&P to put them in for under $300, go for it...I must have had 6 hours into the project (putting the clamps on the frame tubing is beyond difficult on the pilot's side...only a mere PIA on the passenger side)

Mike

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On 9/2/2018 at 3:10 PM, MIR2018 said:

the switch should be in the down position to do this? Or did you mean to say "with the switch in the up position"

Oops sorry - yes switch should be in up position.  You can do it in the down position but you'd have to release flaps up every time and also can cause damage by hitting hard against the stop if pumping vigorously when they go all the way down. 

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My M20C always required...

1 pump to pressurize the flap system... and 3 1/4 pumps to go full down....

low hydraulic fluid kills the flaps operation before the brakes fail...

only happens once... replacing some old hoses cures the simple problem.

 

For the alternator on/off switch... that is a modernization... all the new planes are doing it...

you won’t need a light. 

You will want it as part of the start-up and shut down procedures...

master on.

Start.

Alternator on.

Avionics on.

 

It is for the safety of all the expensive electronic devices...

PP thoughts only, not a mechanic...

Best regards,

-a-

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I agree with the above post. When your flaps do not operate as per the manual 2 pumps till TO position and 4 1/4 for  full flaps then your brakes will begin to fail next. Are you able to set the Parking brake so that it holds the aircraft? Another indication of low possible low fluid level in the brake/ flap  system reservoir.  If leak is not obvious, fill, bleed(properly) until operation normal , then search for leak while operating brakes and flaps, not hard just time consuming (belly panels)

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7 hours ago, carusoam said:

My M20C always required...

1 pump to pressurize the flap system... and 3 1/4 pumps to go full down....

low hydraulic fluid kills the flaps operation before the brakes fail...

only happens once... replacing some old hoses cures the simple problem.

 

For the alternator on/off switch... that is a modernization... all the new planes are doing it...

you won’t need a light. 

You will want it as part of the start-up and shut down procedures...

master on.

Start.

Alternator on.

Avionics on.

 

It is for the safety of all the expensive electronic devices...

PP thoughts only, not a mechanic...

Best regards,

-a-

So, I'm still curious... The Ammeter is only going to show Load on the Battery? So if the Field switch is engaged, the battery is going to charge off the alternator and the ammeter will show a positive indication?  If the alternator fails, whether the field switch is on or off, the ammeter will show a discharge?  So I'm not seeing a Amp load on the whole system just the condition of the battery either charging or discharging?

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16 minutes ago, MIR2018 said:

So, I'm still curious... The Ammeter is only going to show Load on the Battery? So if the Field switch is engaged, the battery is going to charge off the alternator and the ammeter will show a positive indication?  If the alternator fails, whether the field switch is on or off, the ammeter will show a discharge?  So I'm not seeing a Amp load on the whole system just the condition of the battery either charging or discharging?

Ammeter shows load on the electrical system, a failure in the charging system or over taxing the electrical system will show up as a discharge (negative)

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MIR,

See if this is helpful...

under normal conditions.... (nothing broken)

1) Switching The Field wire on... enables the alternator to put electrons into the electrical system... (electrically turned on)

2) having many electrical devices on, will try to drain electrons from the system... (heavy electirical load)

3) Not turning enough rpm, will generate too few electrons, and the battery will start to drain... (taxi challenge)

4) If the battery is draining, the ammeter needle will be deflecting into negative numbers... (a low voltage indicator may go on)

5) There are a lot of transitory challenges that occur upon Engine start.

6) keeping the alternator out of the engine start-up Transition is a fair idea... (most vehicles you may have, don’t do this, or do it automatically?)

7) the next transition comes with the alternator system start-up... keeping your electronics out of the alternator start-up is a fair idea...

8) In the end... you have started the engine and stabilized the rpm.  Started the alternator and stabilized the voltage.  Then turned on the electronics with the least possible risk of voltage spikes... modern electronics are pretty well protected from these transitions. Glass panel engine instruments are especially capable of withstanding the engine start-up battery drain, followed by high rpm over-voltage...

 9) If you taxi with the throttle pulled all the way back... you may not generate enough voltage to keep from discharging the battery... some.

10) if you raise the throttle because you are getting a low voltage warning.... and the low voltage warning doesn’t go away...  check to see if you forgot to turn on the alternator... :)

11) for the un-normal things... the field wire is one of the more common alternator failures... a connector can break from all the vibration it endures... an easy thing to find when it fails...

12) alternators are generally considered less dependent on rpm than generators... but, at 700 rpm they are not producing very many electrons.

13) roughly speaking... it is best to use what you have to avoid exposing your electronics to transitory voltage issues.

PP thoughts only, not a mechanic...

Best regards,

-a-

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Just a few additions to what has already been said:

1) I have sorted out a number hydraulic flaps on vintage Mooneys. My experience is that the system has no requirement to "pressurize" the flap system. My flaps come down as if there is a mechanical connection to the flap handle...if it moves, they move.   Also, regardless of the range given in the MM for number of pumps to full flaps, both systems that I have serviced required precisely 4 pumps to get to full flaps. By precisely, I mean that any pump beyond 4 results in hydrostatic lock of the pump handle.  

2) Inertia reels are nice to have for the pilot side.  An inertia reel on the right side makes an already awkward ingress and egress to the rear seat even more awkward.  The static harness is lower profile and is less obtrusive. 

 

Edited by Shadrach
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1 hour ago, Shadrach said:

every system that I have bled has no requirement to "pressurize" the flap system. My flaps come down as if there is a mechanical connection to the flap handle...if it moves, they move.   Also, regardless of the range given in the MM for number of pumps to full flaps, both systems that I have serviced required precisely 4 pumps to get to full flaps. By precisely, I mean that any pump beyond 4 results in hydrostatic lock of the pump handle.  

Yep- that's how mine works.  

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9 hours ago, DXB said:

Yep- that's how mine works.  

I'm glad yours is functioning as it should. It seems as though there are more than a few of these planes flying around with flap systems that are not in proper working order.  They are simple and reliable systems.  IIRC the MM calls for filling from the top and bleeding from the bottom.  I think this is sub-optimal.  after maintenance I have always done my initial fill from lowest point in the system which is the "T" fitting on the flap actuator (not the pump).  I have had good results with this method, but it can be messy and challenging to seal the system without it sucking air. Can be easily purged though.  It really takes two people to do it right, but it can be accomplished solo with care.

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14 minutes ago, Shadrach said:

They are simple and reliable systems.  IIRC the MM calls for filling from the top and bleeding from the bottom.  I think this is sub-optimal.  after maintenance I have always done my initial fill from lowest point in the system which is the "T" fitting on the flap actuator (not the pump).  I have had good results with this method, but it can be messy and challenging to seal the system without it sucking air. Can be easily purged though.  It really takes two people to do it right, but it can be accomplished solo with care.

Rebuilt the pump/valve several years ago, actuator was done a few months ago. A bleeder valve would solve the mess problem

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The minor change kit you get with the shoulder harnesses has a clamp that attaches to a tube to mount the initial reel or upper shoulder mount. The nut that goes on this clamp is a PIA to get a nut on because it's behind the interior panel, LASAR sells one that has the nut welded in place. That dumb nut was the worst thing about the shoulder harnesses. I've since changed to the LASAR clamps with the welded nut, thanks to the guys here on MS... and LASAR.

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  • 8 months later...

When I bought my M20C it was doing the same thing. Like the others have said It was the pump o-ring.                                                       P.S. Never leave hydraulic flaps down on the ramp. The heat will cause the fluid to expand and blow the o-ring.

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  • 1 month later...

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