In the Repair Manual/Field Guide on pg.161 it states
Whenever the PRINT HEAD is replaced,
the corresponding adjustments must be carried out.
See Chapter 5 "ADJUSTMENT" (p190)
I believe this only applies if you've actually replaced the print head.
If you have simply taken it out and put the same one back in, then I do not believe you need to run the adjustment. The adjustment actually resets the counter of the print head, which you wouldn't want to do with the same print head.