Vehicle report
Technical service bulletins are instructions a manufacturer sent its dealers about a known fault. They are not recalls and the work is usually not free, but they are the clearest signal of a problem the manufacturer already knows about.
511869FRB
According to General Motors Recall 24V702: "The brake lines in these cutaway vehicles may not meet the recommended clearance to the GM-provided body mounts. If brake lines contact the body mounts, the brake line may experience wear or damage that could lead to a brake fluid leak. A brake fluid leak can result in reduced stopping performance or inoperative service brakes, increasing the risk of a crash."
051694FRBV2
According to Navistar Recall 23V397: The brake pressure switch may allow the brake fluid to seep past the diaphragm seal into the brake pressure switch electrical connector and associate fuse which can short the switch and/or fuse. A shorted switch or fuse may cause the circuit to generate excessive heat which can result in an increased risk of fire.
Complaint counts are reports filed with NHTSA, not failure rates. A common model collects more of them than a rare one that breaks more often.