One thing I always did in my position was to cultivate relationships with everyone from the custodians & building engineer up to the senior faculty and department chair. By helping them when I could, I found they were much more willing to help me when I needed it. Life is easier if you're simply nice to people.
Then last boss was hired, and all those carefully cultivated relationships went straight out the window in terms of assistance for our unit. Fun part was, they would bypass the boss and come straight to me to see if we perform the tasks they needed, or if their work could be expedited in any way, etc. I would do what I could for them, and/or encourage the boss to reach out & negotiate, but it REALLY pissed the boss off that they would approach me first...and I would hear about it later. Really hard to not just tell the boss "you reap what you sow, you ####".
Finally pretty much told the boss that when I walked out for the last time...but I didn't cuss. I'm very proud of myself for that restraint!