Top of the Grapevine, lost all air pressure!

The "Grapevine" is the mountain pass on the "5" descending into Los Angeles, the summit a little over 4,000 ft. On Sunday, around noon, I was just beginning the decent and felt the ride getting stiffer, like when you leave a campground before the air pressure has built all the way. I checked the pressure gauge and it was falling quickly! Luck was on my side as there was no one in the right lane. I pulled over but by now the Bus('06) had fallen on to the bump stops and it was bouncing us out of our seats. Again thanking my lucky stars, there was an off ramp in sight but by now my low pressure alarm was blasting and we were feeling some panic, just waiting for the brakes to lock up. We did get off the freeway and, lucky again, got to a parking lot and shut it off. I dropped the jacks and proceeded to look for the cause. After starting it up I was able to find the leak, it was the air dryer, a cylinder about ten inches around and over a foot in length. It is located at the rear just under the front of the motor. Meanwhile DW was on the internet and had found the Freightliner hot line. It is manned around the clock every day of the year, and, a real person who speaks English answered. He helped me through the diagnosis and suggested the fix. I took off the two air lines, air in and air out and connected them together, bypassing the dryer and it's leaking pressure relief valve. Problem solved! I drove it into our winter spot here in Mesa with no other difficulties. The air pressure was a little higher, around 145, but was assured there would be no problems. It is time to buy the rebuild kit and get my next lesson on maintenance! Bob