Had an interesting occurrence on Tuesday night... was cranking along on the Mesquite ride with the gang, and just before we got to the 7-11 stop after 20 miles, suddenly I had no right brake stopping action!!! Pulling on the lever did NOTHING... Fortunately, there is very little brake steer on the SprintX, so I was able to just use the left brake for the last mile or so.
Being a hydraulic brake, I figured that I had somehow lost fluid -- but examining it in the parking lot, I couldn't find any oil residue or indication of leak. I looked at the brake, and saw something moving against the rotor when I pulled the lever, but no clamping was happening. It was a total mystery. Wound up shortcutting back to the start, with a couple other riders.
I took the trike down to John's and left it. When I talked to Patti later in the day, she said: "Your BRAKE PADS were gone!!! The screw that holds everything in apparently vibrated loose and backed out, and the spring and both pads fell out!"
Holy crap.... and I didn't even realize it when I looked at it, not expecting NOTHING to be there...
So, Patti scavenged brake parts off of their floor model (thank you!), to get it fixed for this weekend's MS150 -- and she locktited the holding screws on BOTH brakes, as a precaution.
HIndsight being 20:15, apparently this is why my right-side braking was squealing every once in a while, on the Sunday Roll ride...