Is it smart to use a home equity loan to pay off car loans, and a line of credit?

smart car

My husband and I need to lower our monthly payments. We have no debt except a line of credit for $60,000 with the payment of $410 and two car loans both adding up to about $25,000 and the combined payment of $1050/mo. So, we are spending about $1400/month for these 3 things. If we got a loan for $110,000 and payed all these off, our payment at 6.6% would be around $700/month. Of course I would always pay more than that per month which would go to principle. Why isn’t this a good thing to do? I realize that getting a new car would add to our payments once again. So, that would not be smart. Other than that, is this a smart thing to do? It seems like it is, but then why don’t more people do this?