First time driving mountains

You need to monitor engine and transmission temperature on the way up. Never Never pull over at crest of a long pull to "let it cool down." Keep it moving at the top to allow the high temperatures bleed off some. Stopping only shuts down air flow and you need to keep moving if possible. After a couple of miles you can pull over if you want. Transmissions build nearly all of their heat if the torque converter is unlocked. Read your owners manual and see what it says about pulling steep grades. On my Dodge Cummins it says to push the tow haul button when towing, and on steep grades put the selector in "2" AND try to maintain speeds above 28 mph. This keeps the torque converter locked and practically no heat build up. I have a quality guage in the output line of the transmission, I know immediately what the fluid is doing.

Going down hill, shifting to a lower gear helps but you must use brakes some. DO NOT RIDE THE BRAKES!! My proceedure is to keep the speed very manageable and when it creeps beyond a pre determined level I get on the brakes rather hard for a few seconds, bleeding off 10 mph or so, then letting off the brakes to allow them to cool. Then as speed creeps back up I get on them again to bleed of 10 mph. This goes on and on until I reach the bottom. If you ride the brakes all the way down they will fade out and you will have absolutely no brakes until they cool down again!!!!!! This proceedure works for all vehicles including cars not towing anything. Brakes will fade when hot.