Bob,
This may not be the fix in your BH, but in my 2005 Landmark with a sink in the slide, two things needed to be done.
1. Replace drain hose with one that is more flexible
2. Properly attach drain to floor under refer and at base of cabinet in slide
Early on, the hose Heartland used was fairly stiff and kinked easily. Replacing it with a hose that was much more flexible was the cure for the kinking. I'd be surprised if they went back to that stiff hose. Perhaps your hose is too short?
Mine leaked as well. Not in the hose but where it transitioned to PVC at the end nearest the sink. By securing the flex hose just prior to these transitions, stress was taken out of the transitions and no more leaks from that.
Hope other Bighorn owners with sinks in their kitchen slides weigh in on this for you.
Jim