I recently got a broken reverb from my friend.
He said that it had had some sag and finally it totally collapsed.
I of course was interested if it could be fixed.
The post could be compressed by hand and did not hold the position.
First I noticed that it was lacking almost all of the pressure.
I have a 125mm RockShox Reverb (A1) in my Enduro bike. The bike was bought second hand and the Reverb had some sag and extended easily if bike was lifted from the saddle. So it was clearly in need for full rebuild but I was lazy and kept riding as it still mostly worked.
Then came winter weather with -10 degrees C, which was enough for the Reverb in its current condition and it didn’t stay up anymore. At home I took it from the bike and it had leaked oil (or something similar but more gooey) under it, no use trying to fix it by pumping more air.