Flap Issue/Not working

[Tahir K]

All right guys I need some help here. In my 1966 Mooney M20 E the flap handle pumps but the flaps do not come down when pumping it to set flaps for takeoff on the ground. However, flaps seem to work just fine (for now) in the air when approaching to land. We have replaced the seals, bled the flaps and adjusted the set screw to see if that could fix the problem but nothing worked. Thanks in advance!

[Prior owner]

How many pumps to get the flaps all the way down in the air?

[Tahir K]

How many pumps to get the flaps all the way down in the air?

5.

[Prior owner]

Just now, Tahir K said:

5.

And to clarify, this isn’t a problem wherein the flaps aren’t staying down while on the ground- they do not pump down at all on the ground, even momentarily, correct?

[Tahir K]

And to clarify, this isn’t a problem wherein the flaps aren’t staying down while on the ground- they do not pump down at all on the ground, even momentarily, correct?

Correct. I can not get the flaps to come down on the ground. I can pump away and nothing will happen.

[Prior owner]

Three things change in flight in regards to the flaps (that I know of): aerodynamic pressure acting on the flaps, the pitch attitude of the aircraft, and ambient pressure. Perhaps your reservoir vent is clogged or only venting in one direction.

Edited July 30, 2020 by PilotCoyote

[bonal]

That's weird,  try doing a high speed taxi and see if they deploy during the run but be ready she may want to take off with the increase in lift.  Can't imagine what could change in flight vs on the ground with such a simple system.

Edit, oh I guess three things could change kind of where I was going with my thoughts 

Edited July 30, 2020 by bonal

[steingar]

Had this exact issue.  Problem was in the pump, and it wasn't an easy fix.  Took my extremely experienced mechanic a solid week to figure out how to fix it.

[Prior owner]

I would first check hydraulic reservoir Level and that reservoir vent flows freely in both directions. The Fitting on the reservoir For the flap is in the side of the reservoir, so if the level gets very low, it cuts off the flaps. The brakes are connected to the very bottom fitting, and will get the very last of the hydraulic fluid if the reservoir level drops too low.

[bonal]

Just now, steingar said:

Had this exact issue.  Problem was in the pump, and it wasn't an easy fix.  Took my extremely experienced mechanic a solid week to figure out how to fix it.

Care to divulge what he did to fix the problem 

[steingar]

3 minutes ago, bonal said:

Care to divulge what he did to fix the problem 

Something about softening a rubber gasket in boiling water to soften it and push in a ball bearing is all I can recall, sorry. I didn't do the repairs and never saw the thing.  LASAR can also do the repairs, but my guy doesn't send things out ever. He was pretty chuffed that he figured it out.  The repaired pump takes an extra pump of the handle, but otherwise seems to be working all right.

[Tahir K]

Had this exact issue.  Problem was in the pump, and it wasn't an easy fix.  Took my extremely experienced mechanic a solid week to figure out how to fix it.

well that's not very reassuring lol

[hoot777]

had problem of flaps bleeding up   i had my pump sent out for overhaul'

[Asif Khan]

2 hours ago, hoot777 said:

had problem of flaps bleeding up   i had my pump sent out for overhaul'

2 hours ago, hoot777 said:

had problem of flaps bleeding up   i had my pump sent out for overhaul'

Can you share the place where you sent the pump and how much was the cost? Thank you 

 

On 7/8/2020 at 7:28 PM, Alan Fox said:

SOLD

 

[carusoam]

Welcome aboard, Asif.

Lasar is often a good place to get parts, and have things OH’d

@Shadrach Ross is good with problem solving flap pump issues...

And if you haven’t seen the ball bearing sitting in the ‘matched’ plastic piece...  This is an experience written about a few times around here...

Best regards,

-a-

[steingar]

9 hours ago, Asif Khan said:

Can you share the place where you sent the pump and how much was the cost? Thank you 

First, I should learn to read more carefully.  My flaps refused to budge no matter what, didn't matter how much I pumped.  As for the repair, it was done by Bob Norman of Norman Aviation at the Parr Airport in Zanesville Ohio.  As for what it cost, I honestly don't recall, but it wasn't much.  Bob took a whole week to fix that darned thing, but he wouldn't charge me for it.  The annual inspection with flap repair, a new glareshield and new strobes ran me about 2700 bucks.

[Shadrach]

Before tearing into a pump that’s working fine in the air, I would thoroughly check it over on the ground with the belly panels off. My feeling is that the solution is likely simple.  Just to be clear the flaps don’t move at all? Not even a few cm? Does the the pump cylinder “feel” like it is filling with fluid or is there a vacuum? 
 

this is honestly the weirdest flap issue I’ve heard of to date.

[Guest]

On 7/30/2020 at 4:19 PM, steingar said:

Something about softening a rubber gasket in boiling water to soften it and push in a ball bearing is all I can recall, sorry. I didn't do the repairs and never saw the thing.  LASAR can also do the repairs, but my guy doesn't send things out ever. He was pretty chuffed that he figured it out.  The repaired pump takes an extra pump of the handle, but otherwise seems to be working all right.

I hope he didn’t charge you for a weeks labour without first check to see how much LASAR would have charged first.  It may well have been more cost effective to send it out to someone who could fix it in a few hours.

Clarence

[steingar]

2 hours ago, M20Doc said:

I hope he didn’t charge you for a weeks labour without first check to see how much LASAR would have charged first.  It may well have been more cost effective to send it out to someone who could fix it in a few hours.

Clarence

Clarence,

I offered to pay Bob for his efforts, he woudn't take it.  I don't recall the exact amount for the repair, but I don't think it was much.

[Lionudakis]

That's an odd one  

[47U]

 

On 7/30/2020 at 12:58 PM, Tahir K said:

Correct. I can not get the flaps to come down on the ground. I can pump away and nothing will happen.

When did you first discover the flaps were not working on the ground and what mx was performed immediately prior to that discovery (if any)?

tom

[Tahir K]

From speaking to Bob, LASAR, and Don...it seems to be the ball issue. I'm gonna have it sent out to be repaired within this week and hopefully I can get more details on HOW it was fixed to share with you guys in case anyone has this issue down the road.

[Tahir K]

 
When did you first discover the flaps were not working on the ground and what mx was performed immediately prior to that discovery (if any)?
tom

Believe it or not the first time I discovered it was when I was doing my first Solo flight in the Mooney. Holding short of the runway, going through my checklists, and I go to lower the flaps. Flaps wouldn't come down so I checked the little notch to make sure it was down which it was. Tried again and got nothing. Looked outside to check both sides of my wings to see if there was any physical damage done to the flaps and there wasn't any. Then I checked my controls just to be sure they were still free and correct. Made the judgement that I had a 7,000 foot runway and I could take off without them easily and so i did. Got in the pattern and they lowered perfectly fine and that's when I got confused.

[Tahir K]

Before tearing into a pump that’s working fine in the air, I would thoroughly check it over on the ground with the belly panels off. My feeling is that the solution is likely simple.  Just to be clear the flaps don’t move at all? Not even a few cm? Does the the pump cylinder “feel” like it is filling with fluid or is there a vacuum? 
 
this is honestly the weirdest flap issue I’ve heard of to date.

Don't move at all. It doesn't even fill like it's filling up. Just feels like I'm pumping the level to no end without any resistance. Seems to be the ball issue. I'll post an update of whether or not they work when I get the pump back from it's servicing.

[47U]

2 minutes ago, Tahir K said:

Don't move at all. It doesn't even fill like it's filling up. Just feels like I'm pumping the level to no end without any resistance. Seems to be the ball issue. I'll post an update of whether or not they work when I get the pump back from it's servicing.

Let’s hope servicing of your pump solves this issue... we’re all curious as to what the shop discovered inside the pump.

tom