circuit breakers

I often fly an early 80's 172RG that recently started having issues with the landing gear after a 2 month maintenance grounding (prop seal fix). The first time was the first flight out of maintenance - the red light (Unsafe Condition) over the green, gear down light came on after lifting the...

Quick and easy question: As the owner/operator of my PA38-112 Piper Tomahawk, as well as a certified A&P, can I replace all the white circuit breakers in the cockpit which reset flush and change them out for the black type which can be pulled in flight? Would that take a 337, or are they...