For the past two years - on and off again - when testing my (emergency gear) hand pump, it was void of hydraulic oil, and wouldn't cycle the gear down. I replaced the three seals on the manual pump, and it worked fine for a few months, but then eventually failed - again, for lack of hydraulic fluid (my hydraulic reservoir was full, and my electric pump cycled the landing gear just fine). The issue seemed to be a lack of (intake) hydraulic fluid to the manual pump, and if the pump cannot draw fluid into the piston cavity, it will "luft" air into the piston cylinder, which results in zero gear deployment.
Solution. There are two check valves - one immediately in front of, and the other to the rear of the hand pump (review the Lancair hydraulic diagram, chap 26, page 6).
Since the new Lancair owners are currently not functioning - and Lancair Intl in Ulvade has no parts, I shopped and found mine online.
- The Hydraulic intake is thru a low pressure poppet valve (# B-6C-1/3) - which I replaced thru Swagelok - https://products.swagelok.com/en/c/fixe ... 6C-1%252F3 - the original valve is brass, but they had the exact same valve immediately available in stainless steel, so I purchased that instead. $139
- The rear, high pressure check valve, is also brass - (# CMM10B1) , purchased thru Trausch Dynamics, Grand Island, NE - https://www.hydraulicstore.com/pneumati ... ltrol.html - $13
Emergency Hand Pump - Landing Gear
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Brad Simmons
- Posts: 15
- Joined: Tue Dec 20, 2022 3:00 pm
Chad, did this prove to solve your issue? Did you find any crud in the check valves?
I have the brass Swagelok in stock, FYI.
TY,
Brad
I have the brass Swagelok in stock, FYI.
TY,
Brad
Brad,
Thanks for checking in! As you recall, we discussed this briefly as you were leaving Oshkosh. In any event, I got lucky - the poppet valve was available locally, and I picked it up the same day. I ordered the high pressure check valve through Trausch Dynamics in Grand Island, NE for $12.59 - in my hands 2 days later!
We installed the valves, and the gear swung just fine up on the jacks - I'm going to cycle the gear normally after a couple weeks, then try my manual pump while airborne. Stay tuned.
Best,
Chad
Thanks for checking in! As you recall, we discussed this briefly as you were leaving Oshkosh. In any event, I got lucky - the poppet valve was available locally, and I picked it up the same day. I ordered the high pressure check valve through Trausch Dynamics in Grand Island, NE for $12.59 - in my hands 2 days later!
We installed the valves, and the gear swung just fine up on the jacks - I'm going to cycle the gear normally after a couple weeks, then try my manual pump while airborne. Stay tuned.
Best,
Chad