REFLECTOR: slow nose gear down indicator

[Scott Baker]

On 2/19/2013 7:38 PM, Scott Derrick wrote:
> Lately my nose gear down(green) light has take longer and longer to 
> light up.   The main green lights up, the gear motor stops, 10-15 
> seconds later I finally get a nose gear green. Actually today it took 
> maybe 25 seconds before the nose green lit up.  I was starting to wonder.
>
> I think my gas strut is getting old,  97 model strut.  Maybe it just 
> doesn't have the umphh to push it over center?
>
> Anybody see this type of behavior?
>
> Scott
>
Hi Scott,

First check the nose gear down micro switch and its mount to confirm the 
switch is functioning as it should and the micro switch mount is solid.

Something other than the gas spring is the culprit.  If the nose gear 
linkage is rigged as it should, the hydraulic ram (by virtue of 
extending itself to its most outward travel) should push the linkage to 
its over-center position.  As you know, when the ram reaches its 
furthermost travel, hydraulic pressure builds and ultimately turns the 
pump off when the 'gear down' hydraulic pressure switch reaches its set 
pressure (about 550psi).  When this happens, the ram should not be 
capable of any further travel.  This is a long winded way of saying that 
the strength of gas strut has no bearing on the travel of the nose gear 
linkage.

Check the travel limits of the nose gear ram to make sure that it is 
providing full travel and the gear linkage is over-center when the ram 
reaches its furthermost travel.  Possible problem areas include loose 
mounting screws at the base of the nose gear cylinder; ram rod end 
bearing turning (though not likely); some sort of blockage inside the 
ram that is limiting its full travel; or major slop in the nose gear 
linkage pivot bolt bearing/bent bolt.

Best,
Scott B.