NOSE STRUT LEAKING Nitrogen in 172-A

After the -15F days this winter, I noticed our bird sat a little higher at the tail, as I'd walk behind it in the hangar. Now that it's warmed up, I have only 2 fingers (1-1/2 inches) showing as strut clearance. The A&P at the next hanger suggested some hydraulic sealant before the top-off with nitrogen. Has anyone else ever faced this kind of minor problem, and how did it work out for you?

Comments

  • I suppose this isn't much of a problem for most owners, but I have learned a little more about it.
    1) In my case - leaking nitrogen but not oil - it's almost certainly a Schrader valve problem, at the top of the strut.
    2) I ran into this newer product, from a company that has really supported Cessna maintenance :
    https://www.mcfarlaneaviation.com/media/documents/why-does-my-cessna-nose-strut-keep-leaking-down.pdf
    This is probably the best solution for nose struts leaking hydraulic fluid.

  • I replaced the Schrader valve assembly, and topped off the Nitrogen. Seemed to be doing well, until another cold night near 25 degrees. I admit this one caught me by surprise, and I didn't have the forced-air heater stuck into the bottom of the cowl. The charge was lost again, and I refilled it. No cold nights like that since, and it seems to be keeping the nitrogen. The nose strut was just overhauled with new seals, about 3 years ago, so what might cause this?

  • Did you replace the complete Shrader valve or just the valve core? There is a crush washer under the valve body that should be replaced when replacing the valve.

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