Brendan hit a lot of it on the head.
Rest, recovery, and planning the right max setup.
Make Sure you are rested and recovered for a good max day.
Learn to get in good reps but not fatiguing yourself. With a possible 255 max I wouldn't do 5 reps of 175 (maybe 3 or 2). Also remember a 20lb jump at that weight may seem like a lot.
235 or 245x1
Rest 3-5 mins between each attempt. Might seem overkill but it's all realitive.
I max squatted Monday and did
255x5 (had put my 45lbs vs 55lb plates on first)
Took 25 mins to work through it.
Good luck, give it some rest and go at it again