will 387.7(a) put my truck out of service
No, most likely not. Across our 13 million inspection records, 387.7(a) citations result in an out-of-service order only 1.0% of the time. Out of 479 all-time citations for this code, just 5 trucks were placed out of service while 474 were allowed to continue. That's far below the national average OOS rate of 31.4% across all FMCSR codes. However, the citation itself will still appear on your safety record and count toward CSA points.