will 387.403(a) put my truck out of service
No. Across our 13 million inspection records, 387.403(a) has never resulted in an out-of-service order. All 5 all-time citations in our database resulted in a citation only—0.0% out-of-service rate. This makes it far less severe than the all-FMCSR average OOS rate of 31.4%, so you can operate your vehicle while you work through the citation process.