[prestadude]

My wife and I traveled down to Phoenix from Sacramento last week to attend my sons graduation from ASU. On the first day about 1 hour north of Bakersfield, I noticed the supply air was dropping although the brake air was fine. The level light on the dash also came on (a thread in another post to this section). Normally both are at about 110 psi. Supply could not get above 70 and would occasionally drop down below 40 psi and the low air dash light would come on. Being so close to my first night destination in Bakersfield, I decided to nurse it along. If the air got too low, I would shift down a gear to kick up the revs and generate more air. That technique got us to the campground (River Run RV Park on Highway 58 W and 99). After some frantic phone calling I located a repair place literally 2 blocks away that would fit me in first thing the next day, Jerry and Keith's Truck and Trailer. I limped the rig over the next morning and that started looking for the leak beneath the chassis and found nothing. There was still air in the bags but the fill valves were in a position to accept air. I would run the engine to get the supply pressure up but it would leak out in a few seconds after I turned off the motor so they really didn't have time to diagnose. The head RV guy (Terry Tillman) hooked up an air pressure line to the supply chuck in the chassis battery bay and cranked up the pressure. A rush of air came from a small air drier to which a pressure gauge was attached. The plastic bowl had split open releasing so much pressure that the engine compressor could not keep up. Terry said the air bags have a safety feature that they will not accept air if the system pressure is below a set point. This helps prevent a situation where suspension robs air from the brakes. The mechanics replaced the drier and I was back on the road by 10:30 AM (at a cost of only $210). You never know what will happen on an RV trip.