Now that the outside temps are warming up popping hydraulics are back.

Here is the technical fix from Lippert:
LIP Sheet - 0295
HYDRAULICS
ADDING ANTI-STICTION FLUID TO LCI HYDRAULIC SYSTEMS
Introduction:
If there is a popping noise in a Lippert Leveling system, Lippert has approved adding a quart of anti-stiction fluid. Approved fluids are listed by brand name and fluid characteristics below:
1. Torco RFF Grade 15

2. Maxima Fork Oil Grade 15

3. Caterpillar Hydraulic Oil Additive 1U-9891 ( NOTE - Experience indicates this is the more effective additive.)

For maximum results in the shortest amount of time, please follow the preparation and procedure exactly as written below. Failure to follow the preparation and procedure may result in delayed resolution of the audible disturbance.
Preparation:
1. Obtain a clean container (large enough to hold a quart of fluid)
2. Obtain a fluid extraction device (siphon, turkey baster, etc.)
3. Fully retract all hydraulic cylinders and Leveling jacks. (Jacks up and slides in. Best to do this when hitched to truck.)
Then:
1. Using the fluid extraction device, remove one quart of fluid from the power unit reservoir.
2. Add 1/2 quart of the specified fluid.
3. Extend all hydraulic cylinders and jacks fully.
4. Add the remaining amount of the specified fluid.
5. Fully retract all hydraulic cylinders and jacks.
6. Run the Auto-Level feature on the Level-Up system per the instructions found in the Owner's Manual.
NOTE: If the noise persists, the addition of a second quart may be necessary. Follow steps 1 through 6

As a side note it has been found that adding blocks beneath the jack feet also reduces popping. The popping most likely results from expansion and contraction of the jacks and coach structure where there are large temperature swings from day to night.