SERVICE BRAKES, AIR:SUPPLY:CHECK VALVE
THE DUAL AIR RESERVOIRS OF SOME TRUCKS WERE EQUIPPED WITH CARBON STEEL SPRINGS INSTEAD OF STAINLESS STEEL SPRINGS, AS INTENDED. THE CARBON STEEL SPRING IS MORE SUSCEPTIBLE TO RUSTING THAN THE STAINLESS STEEL SPRING. THIS RUSTING COULD CAUSE THE CHECK VALVE TO FAIL, CAUSING TOTAL LOSS OF FRONT AND REAR BRAKES.
Remedy: THE AIR TANK WILL BE INSPECTED AND, IF NECESSARY, THE AIR VALVE WILL BE REPLACED WITH ONE CONTAINING A STAINLESS STEEL SPRING.
3,948 vehicles affected