These are Anna Wittert's notes from Leymeybamba to Celendin, in northern Peru:

km 426 / 2300 m Leymebamba
km 396 / 3600 m top of the climb, there are waterstreams on either side of the pass, not so much or unclean water lower down
km 376 / 2500 m restaurant (blue building, i think the one you stopped at as well, cause all the busses have a break at this one, we were allowed to camp and cook inside for free as it was raining and the slopes closeby to steep to pitch). They have a watertap outside. The town is called saulluma, and the restaurant Diegito, but there are no signs to tell you so.
km 336 / 980 m Balsas (shops and I think a bad hotel)
km 331 and km 324 reasonable looking campspots, although hot and with a lot of cactus
we carried 20 l of water from the first pass down and used that at the restaurant and carried the rest for the next night. Not really necessary in the end, although it was nice to drink fresh mounbtain water for a change...
the climb from Balsas is a little bit steeper then the one from Leymebamba, especially the bottom 20 km
km 315 Limon (small town)
km 314 a small track in a sharp left bend on the right side of the road, lined by an old stone wall, leads to farmland. We asked the farmer and camped some 40 meters away from the road. No water on site. Awesome birds both evening and morning.
There are a few more suitable wildcamp spots further up, but all visible from the road. The cliffs get too steep for camping after a while.
km 293 / 3145 m the top! good camping options if you don´t want to go to town
km 281/ 2680 m Celendin