151 Semaphore

@JKK posted:

Anyone experience "Flag Sticking" in downward position?  I'm inclined to shoot graphite into the support arm opening where the spring is located, but I'm hesitant 'till I get feedback from the SMEs (subj matter experts) in the field.  I should note I'm running (been running) the accessory using a button connected to fixed voltage.  Please "dummy proof any/all replies - thanks in advance.   

   

I have a railking that had did that also, I tighten down the shoulder screw on your 151 that should help, I also did take mine apart and clean the arm and added some lithium grease. Hope that helps good luck. Mark

appreciate you taking time to send a reply; i'll give the grease a try.

I removed the top cap and lubricated the inside of the entire vertical post with lite weight lubricant. This worked much better than only dealing with the top elements.

The solenoid can also be in need of lubricant. Just because you witness the problem at the arm, the cause may be elsewhere...

Greenberg's Repair Manual is a great investment if you have Post War equipment.  The problem you describe is outlined in the manual and involves checking the rack and pinion  engagement position when the arm is down, plus making sure there is no waxy buildup on the piston or inside the solenoid. A weak return spring can also be an issue.  The ones I have, usually a good cleaning and making sure nothing is rubbing inside cures it.