I can't imagine spending/needing 2hrs at the Valle de los Caidos!
I found it very sad and inside it gave me the chills.If indeed you feel you must go,then the ride to it is pleasant enough-look for the 12 stations of the cross set up in the mountains.The funicular was always broken when we took friends.
The tour of Escorial is a bit much.I suggest reading up on it before you go. The round crypt where the kings/queens are buried is interesting but there are loads- too many- of royalty buried in another area.The library is amazing.I happened to be there when a wedding was just finishing-can you imagine being married there?
Near the main entrance is a great restaurant,La Cueva.Doesn't look like much from the outside but we had a fabulous lunch,great atmosphere.They do have a website.
My friends said that they called a couple of hotels and even though they were not staying in Escorial,they looked after there bags for a small fee.
By the way the drive back to Madrid is a very busy highway-be prepared-pretty much all defensive driving,like the rest of Spain!You are in for a looooong.
I would go back to Madrid and take the bus to El Escorial,easy,relaxing way to it.