Bleeding of hydrolic flaps.

[skycop]

I let the fluid for my flaps get too low (small leak since fixed). Since I added fluid and bled the system, the flaps will NOT retract when the flap lever is put in the "retract" position.  I can only get the flaps to retract by opening up the bleed valve.  Further more, I can lower the flaps regardless of what postion the flap lever is in!  Do I still have air in the system?  Would loosening the screw that governs how fast the flaps retract help to get the air out of the lines (if air is the problem).  I'd appreciate any help or suggestions.  Thanks

[carusoam]

Easy solution, may require the help of another person (make it a mechanic and you've got it all covered).

My 65C had a similar experience.   Your flap actuator now needs adjustment.  A very small movement is the difference between open and closed (flaps up or down).

Check the action of the flap valve on the hydraulic cylinder.  Up should release the pressure.  Down, should make it build pressure.  Total movement is very small and sounds like you are going from closed to more closed....  This is difficult to do without help.

If I am not mistaken, keep in mind that the brakes are using the same fluid.  (I don't think this is your problem though)

If the flaps go down, the air is mostly out of the system.  Air in the system will keep the flaps from going down.   If you pump several times more than usual and little happens...  Keep cycling the flaps up and down, air should disappear quickly.  (again probably not your problem)

I think 3 pumps pressurized the system and about 4 pumps moved the flaps from full up to full down. (no air)

Now that you have moved the position of the bleeder valve....  From the service manual there is a recommendation on how long it should take for the flaps to raise.  You would not want the flaps to go up instantaneously during a go around.

This "time" is somewhat difficult to set.  I used hand pressure on the flaps to get close.  Unfortunately, I don't think you will know how good you are until the sheet metal is back on and wind supplies the pressure on the flaps. 

I did this adjustment with my mechanic during one of my annuals.

- anthony -

[scottfromiowa]

I had a flap "incident" last week.  Took a short trip of about 30 minutes (to show my mechanic a couple of updates) and on short final whent to pump flaps down and...nothing.  No pressure at handle.  Brakes still functioned and taxied over and ultimately had to bleed air out of system (remove belly to access) and ended up pulling hydraullic valve and replacing gaskets.  Had to force hydraullic fluid through reservoir/add and pump like mad to eliminate air/get flaps to function.  I had a small leak also that allowed air into brake hydraullic lines.  I don't always use flaps when light/just me, but will now make 100% certain I cycle flaps when family/added weight and necessity to have flaps is present during pre-flight.  I hope you resolve your issue O.K.  Good stuff on the solution Tony.  Scott

[skycop]

Anthony... adjusted the small screw adjustment for the flap raising speed and all is well:).  Thanks for the info...Ray