Replace air compressor mounting gasket, replace front crankshaft seal and replace the gear cover to eliminate oil leaks. The drive belt that was installed by Cummins Atlantic was the incorrect one and a new one was installed by Cummins Mid South Kenner. The oil leaks were noted by Freightliner in Gaffney, SC during a routine maintenance inspection. They recommended that Cummins Atlantic in Spartanburg, SC be used to repair the unit. I took it to Cummins Atlantic and they added a fluorescent dye to the lube oil and used a black light to pinpoint the leaks. They recommended replacing the air compressor gasket and gear cover. The drive belt also needed replacing because of oil contamination. Unfortunately it would take a week or more to get the gear cover. We could not wait that long so we returned home to LA after replacing the drive belt. I took it to Cummins Mid South in Kenner and told them what Cummins Atlantic had found and recommended. It took about a month for Kenner to confirm what Cummins Spartanburg had originally recommended. Moreover, Kenner replaced the lube oil and dye with 22 quarts of oil with dye which was still in the engine from the visit to Spartansburg visit. The VIN specs for my Cummins engine are a 17 quart capacity. I rated the quality of service a poor because 1) the service manager was unprofessional throughout the exercise, 2) my engine holds 17 quarts and they put 22 quarts in it which I was unaware of until I reviewed the invoice and 3)they charged me for two seal kits. I drained 4 quarts of oil after confirming that the oil was 1 inch above the full line on the dipstick. They did successfully replace the drive belt. The drive belt that Spartansburg had installed a month earlier was not the proper length and was slipping on the return trip to LA.