servo autobed levelling

hello,
i'm trying to use servo
i configured everything like offsets from extruder, probing points,
when i give G29 command
servo extends and then probes to first point, and then it doesnt retract and keeps moving from one point to another
i want to retract my servo at every probing point so i can avoid any crash.
please help,

my servo doesnt retract like it happens in this video [www.youtube.com]