Only if none of your conventional places can work on your equipment. Like if you needed tranny work in your car you wouldnt take it to Midas you would take it to a tranny shop and expect a higher rate because that is all they do.

Otherwise you need to stay in line with your competitors. Possibly leave the labor rate the same and mark up travel expenses for the out of town calls. It doesnt have to be much 5 or 10%. And the customer still feels good about your service department.