Problem with Pentair Legend Krauler

My legend krawler is acting badly again. This time the front wheels ride off the surface of the pool bottom, like its in perpetual wheelie mode. I have made all kinds of adjustments to the jets in back. But still wheels up. This basically means that it doesn't pick up debris very well. I've replaced the tires, and a bunch of other parts. Its 5 years old. In the past I've replaced a couple of hose swivels and thinking about replacing all three this time.

What should I do short of pitching it and getting something new.