This is what is recommended for most Duramax power steering pumps, I have used ATF but have switched to it, yes it is expensive but the pump is quieter and don't cry like that I'll use this.
🚗 Honda 08206-9002PE Pack of 3 Power Steering Fluid – Enhance Vehicle Performance
7 Review
Genuine Honda Fluid 08206-9002 Power Steering Fluid - Superior Performance in a Convenient 12 oz. Bottle
8 Review
LIQUI MOLY Oil-Verlust-Stop, 0.3 L
11 Review
🛢️ ACDelco GM OE 10-4017 Auto-Trak II Transfer Case Fluid - 33.8 oz
9 Review