14-19-3 Nosewheel Retract

SoCalPlaneDoc

SoCalPlaneDoc

New member
Probably not interesting to taildragger folks

I overhauled the nose gear retract cylinder.. easy.
But after reinstalling I noticed the *extension* behavior changed slightly (retract seems the same).
Before: mains down first, then nose would lock.. maybe 2 seconds later.
Now: nose down first, and quickly!...mains 2 seconds later. I also get a squirt of fluid out the upper reservoir vent. (no, the fluid level isn't too high)

I'm thinking that despite all my efforts, there is air in the system on the down-side of the gear *retraction* line. Since it offers less resistance as it leaves the cylinder during extension, the gear goes lickety-split..

comments? (constructive ones please) :)
 
I think the "burping" at the reservoir is diagnostic of air being purged from the system.

So, I'd keep a constant eye on the level, while it settles in.

No experience with the rest.
 
Was the nose wheel cylinder very dirty before you rebuilt it? You may have improved its performance(and reduced friction) enough that it works better than the main cylinders. The mains are just as easy to rebuild, and I believe take the same O-rings. A friend with a 14-19-3 learned that on the ground, if you hit the retract lever, the mains retract first. He managed to save the prop, and get some friends to help lift it high enough to pump down the mains again, and go back to the hanger. He was a little shaken, but very lucky. ______Grant.
 
gjordan said:
Was the nose wheel cylinder very dirty before you rebuilt it? .
Click to expand...

Nope, it was beautiful. I only pulled it off and changed the o rings since I had removed and rebuilt the nose strut.
The system is an open-center parallel plumbed system. The friction of the fluid *leaving* the cylinder along with the airflow used to cause the nose gear to initially drop, but then pause as the airflow helps the mains go down. Once the pressure builds up again, then the nose strut is pushed the rest of the way down.
So my theory is, there's not enough fluid in the up-side so there's nothing to resist the gear going down, and the initial momentum carries it all the way through. I cant explain the lil squirt of fluid I get out the upper reservoir though. I do know that it only happens when the gear goes down fast, like when it's on the jacks.
I'm going to put it up on jacks this weekend and see what gives. Maybe I'll get someone to pump it down whilst I crack the fittings, just to see if I get any air out of it.
 
I don't know a whole lot about nose wheels. On 14-19-2s if the top reservoir is over 1/2 full there is not room for fluid as the mains retract and it will escape out of the hole on the plug on the top reservoir.
 
glennhake said:
I don't know a whole lot about nose wheels. On 14-19-2s if the top reservoir is over 1/2 full there is not room for fluid as the mains retract and it will escape out of the hole on the plug on the top reservoir.
Click to expand...

ya, verified the reservoir is not overfilled, and the "squirt" occurs on gear extension.
Cowl comes off today, I'll be looking into this.

I wonder if anyone has ever written a "best practice" procedure for adjusting the reservoir level? I've never seen one that I can recall.
 
OK, I was wro.. err wron.. err incorrect :)

the 5606 leak is actually just a little oozing from the gear-down hose fittings - tomorrow I'll fix that. I noticed today though that when using the hand pump to pressurize the system at extension (It falls all the way down on it's own), the gear handle didn't pop up like it usually does.. sorta came up half way and stopped.. hmmmm.. have to see what it does in the air when I get there again. But.... I've had an oil leak since I got it that I cant get to with the engine in the plane so, since I had the cowl off anyway....
EngineOff_zpsb0fdb5a1.jpg


Did I mention I oil leaks *really* bug me?
:)
 
We're flying again.
Ended up removing everything off the bottom and back of the engine and replacing all the gaskets. Most of them turned out to be wet on both faces indicating that they weren't sealing very well. Also put a REAL gasket on the oil pan, scraped the case where the oil pumped covered the case seam (it wasn't as flat as I like it), replaced the wet pump with a dry type and deleting the pump exhaust condenser entirely. Repainted the entire cowl and spinner to get rid of those pesky screwdriver scars from previous owner(s). After a 2.5 hour flight doing IFR currency approaches, not a drop of oil showing anywhere.. life is good :)

N8805Raftergasketwork_zps86b2f968.jpg


Going to rebuild the mains as soon as I move to my new bigger hanger. In the mean time, back to working on the new panel!
 
March to June... why does that sound so familiar ? !!

Congrats.. it really IS satisfying to conquer the leaking oil devils.

$3000 worth of work and $ 25 worth of gaskets .. :roll:

Lovely plane !
 
Thanks guys.

Blimp - oh were it only $25 for the stuff. the starter adapter gasket alone was over 40 bux. Then there's the REAL oil pan gasket, new vacuum pump, $150 for paint, etc....
But I long ago stopped justifying planes using costs. It's just cheap therapy. :)
The Garmin radio stack that's going in it is worth it's weight in gold.. literally. Careful shopping made it feasible (along with installing it myself since, I don't charge myself very much).
When I'm done I'll have spent more than it's worth. that probably sounds familiar too.

But when ATC asks me to make a course change because I'm overtaking a quarter-mil Bonanza..
When the airport rats ask me what it is at the fuel island..
When the Examiner expresses surprise I brought a 55 year old plane to my commercial flight check, then asks if he can fly it and is delighted..
When the local EAA chapter has me park it in front at it's monthly Saturday breakfast and it's not even a homebuilt.
It's all worth it.
I spent yesterday afternoon crawling under my panel to figure out how I'm going to install my HSI into the panel. Look for my picture on the cover of Popular Physics magazine when I receive the award for fitting 3 1/8" instrument into a 2 1/2" hole :)
 
You must log in or register to reply here.
Back
Top