I got so frustrated doing this quest chain - the Kraul is such a confusing warren! By the time I got to this quest, I was so turned around and swearing my head off. Back at the quest giver I nearly kicked myself when I realised how much time I had wasted. So I am here to share some directions:
Standing next to the quest giver, facing the same direction (looking into the Kraul) you want to take the path to the left that heads up. All three caves are quite close together and on the top ridges. Don't go back down into the warren. I have shared a screenshot where you can see the path, the quest-giver & all three caves.
You will come to the Central Stockpile first (cave entrance is at 45.6, 78.2) once you come out (your back to the cave) you turn right heading up the path rather than back down where you came from. The Eastern Stockpile (cave entrance is at 46.3, 78.1) is literally right next to the central one. With your back to the cave again, you want to take a left, walk past the cave the central stockpile was in and continue up the path. It splits in two, one going further up or under a huge thorny vine arch with a torch under it. Take the path under the arch and the last cave is just a little way from there where you will find the Western Stockpile (cave entrance is at 43.6, 78.5).
Hope this helps and is clear.