Flaps Retracting slowly

[Lancer11A]

I'm at a lose.  History: Flap pump failed due to link.  Rebuilt and worked great until the flap actuator failed.  Rebuild actuator, no leaks.  Flaps worked for about a week.  Flaps started to retract slowly when put in any position, T/O to Full.  rebuilt pump again.  same results.  Had my AI rebuild a third time and make sure all adjustments were correct.  Flushed hydraulic fluid.  Still the same results.  Anyone have the same issues?  What am I missing?  Thinking about converting to electric.  

 

M20C

Paul

 

[N201MKTurbo]

You just need to adjust the retract rate. It is kind of touchy, but there was no need to rebuild it multiple times.

You say that all the adjustments are correct after saying they aren't.

[Lancer11A]

We have adjusted the retract set screw with no change.   Will check it again

Thanks 

[Lancer11A]

Maybe I didn't explain the issue correctly .  Once I've selected the flap lever to pump the flaps down, pump the flaps to the desired location (T/O or Full) the flaps will retract slowly while the lever is still in the down position.  I have not selected the lever to the flap up position.

[RLCarter]

7 minutes ago, Lancer11A said:

Maybe I didn't explain the issue correctly .  Once I've selected the flap lever to pump the flaps down, pump the flaps to the desired location (T/O or Full) the flaps will retract slowly while the lever is still in the down position.  I have not selected the lever to the flap up position.

Do they work correctly then after a few days start to bleed off when deployed and and flap lever (cabin) is in the “flaps down” position?
 

[Andy95W]

If it’s not the retract rate screw like Rich said, then it sounds like it’s the lever that’s connected to the piano wire that goes to the cockpit.  That is also very touchy, if it’s not quite right it will allow the hydraulic pressure to bleed off.

[Shadrach]

3 hours ago, Lancer11A said:

I'm at a lose.  History: Flap pump failed due to link.  Rebuilt and worked great until the flap actuator failed.  Rebuild actuator, no leaks.  Flaps worked for about a week.  Flaps started to retract slowly when put in any position, T/O to Full.  rebuilt pump again.  same results.  Had my AI rebuild a third time and make sure all adjustments were correct.  Flushed hydraulic fluid.  Still the same results.  Anyone have the same issues?  What am I missing?  Thinking about converting to electric.  

 

M20C

Paul

 

Paying someone who doesn’t know what they’re doing to repeatedly perform maintenance that isn’t correcting the problem is not really the flap system’s fault. The system is theoretically simple but it has some challenges and quirks to contend with. 
 

Most likely culprit is that the retract cable slipped out of position in the clamp after a few operations thus affecting how the cam opens the return circuit. There are few logical reasons to rebuild a flap pump because of a slow flap retraction, especially given how the problem manifested. There are a number of external adjustments and tests that could be performed long before opening the pump. IMHO, It would be a bad idea to pay someone who couldn’t sort out a hydraulic pump to do an electric conversion.

[Shadrach]

6 hours ago, Lancer11A said:

Maybe I didn't explain the issue correctly .  Once I've selected the flap lever to pump the flaps down, pump the flaps to the desired location (T/O or Full) the flaps will retract slowly while the lever is still in the down position.  I have not selected the lever to the flap up position.

How do the flaps feel when you manually push them down from the up position? Does the return spring feel strong? Do the flaps feel like they’re binding?  
Next, remove the belly pan. Remove the retract cable from the lever on the side of the pump . Have a helper pump the flaps down. Manipulate the lever in various positions to see if you can improve the return speed.  Ever have a bicycle derailleur stop shifting properly because of cable stretch or poor adjustment? Similar situation.

Another possible but unlikely scenario is that there is FOD clogging the return circuit in the pump.

[Kelpro999]

During valve reseal, pay close attention to the 1/4” steel ball and seal (HE-1517).

[Jim Peace]

5 hours ago, Lancer11A said:

Thinking about converting to electric.  

M20C

Paul

 

Can that be done?

[Old Chub]

Had a similar issue.  It was as Kelpro999 talks about.   I had to re-stake the check ball in the nylon seat (inside the pump) to get my flaps from bleeding back.

M20C

Warren

[Shadrach]

1 hour ago, Old Chub said:

Had a similar issue.  It was as Kelpro999 talks about.   I had to re-stake the check ball in the nylon seat (inside the pump) to get my flaps from bleeding back.

M20C

Warren

Which seat? Good idea to stake the ball to seat any time they’re separated.

[Rjfanjet]

I sent my flap pump for an overhaul. No issues since. LASAR did the work.

[Kelpro999]

5 hours ago, Shadrach said:

Which seat? Good idea to stake the ball to seat any time they’re separated.

The only 1/4” ball. Between pump and valve body. It’s the pump check valve.

[N201MKTurbo]

From your further description of the problem, you need to re-stake the retract check valve ball and seat. Sorry for the confusion.

[Shadrach]

10 hours ago, Kelpro999 said:

The only 1/4” ball. Between pump and valve body. It’s the pump check valve.

Yeah, I was totally thrown by the subject line description  and some of the earlier posts. I read “slow retraction” and thought that his flaps weren’t coming up fast enough. Clearly I wasn’t the only one.
It obvious now that his flap will not stay down. I agree that staking the valve to the seat is the best course of action. 

[Lancer11A]

Great conversation with all.  Thanks for the input. Turns out the issue was the nylon seats where bad.  Replaced   All good