quick question..30,000 miles servicing

Considering that most RV chassis are being worked at or near their gross design weight just going down the road with little additional weight inside, Changing all fluids on the manufacturers schedule is prudent. I also change all fluids, belts, hoses on schedule or every 5 years whichever comes first, and on all used vehicles when purchased. Keeping fluids and all rubber parts (including tires) in good shape will eliminate 90% of the breakdowns you see along the highway.