A question from Barry in MM:
I’m seeing some red fluid in the right landing gear area of my retract, and I sometimes feel some buffeting. I’m having trouble keeping the right gear door seal in place. What could be wrong?
Before you get into overhauling your MLG actuator (you won’t want to buy a new one, even if you find it), some questions/suggestions.
1. Have you found the source of the fluid leak? I am asking because you also have a MLG gear uplock cylinder. In my experience, the MLG uplock and NG downlock cylinders are the most prone to external leaks, while the actuators themselves are the most prone to internal leaks.
2. It is a piece of cake to overhaul the uplock cylinders. The two key aspects are to make sure the proper Mil-spec o-rings are used, and that the operating shaft is well-polished on a buffer before being reinstalled (with a dab of Parker-Lube).
3. The symptoms may also imply that the uplock is not engaging. That would let the gear bounce in the well, causing seal damage and buffeting. Has the rigging been checked? There is a specified clearance between the uplock arm and the flat on the gear. I am away from my books and can’t look it up for you. Sometimes you can see paint damage on the gear housing where the lock engages; a possible sign of incorrect rigging.
4. There is a rubber-nosed bumper bolt on both the MLG and NG, intended to snub the gear in the up position. If improperly adjusted or damaged, the bolt can prevent full retraction, or can permit bouncing in flight, or can damage the housing.
Be sure this all gets checked out before deciding to fix anything.
NOTE: This member’s follow-up revealed a definite leak on the right MLG actuator. He will have the o-rings replaced in it, and will have all these other items checked as well.