Driving from Dallas to Anaheim on I-40

The proponents of the old theory have rescinded it, there is now (almost) universal agreement that the proper way to brake on a downgrade is to intermittently apply all your service brakes in a way that will reduce the speed of a fully loaded vehicle by about 5 or 6 mph during each application. Not agressively, enough to apply all brakes. The only hills that you might get hot on is the one out of Flagstaff Wbnd and Cajon Pass on I 15 going into San Bernardino. It is long and steep. You could avoid Cajon and go S on 95 at Needles, make sure you fuel there, to Vidal Jct, west on 62 to to Palm Springs and over Banning and the downhill side of it is 55 MPH coast all the way to Redlands. Drove big trucks out there for years. Coming back you can take I 15 and I 40 as down hills aren't all that bad, 1 coming into Needles EBND is steep.