Recreational Vehicle Lpg Tank Valve/gauge problems of the 2008 Chevrolet Suburban

I was driving on the road when I had heard a creaking noise coming from my dash area of my 2008 Chevrolet Suburban. When I came to a stop, I looked at the dash and did not notice anything loose or that what cause this noise. As I continued to drive, I noticed the noise again and noticed my dash was cracking in two different places. One crack by the passenger airbag and the other on the left side of the gauge hump on the dash. The crack by the airbag is about an inch and a half. And the one on the drivers side is about 3 inches long and still growing. I tried to seal the cracks with silicone, and that did not work.