PACCAR issued a recall on the T300 model

Certain vehicles having an intended service code of "Fire Service" and either Type 24 or larger front brake chambers or Type 36 rear brake chambers fail to comply with requirements of C.M.V.S.S. No. 121, "Air Brake Systems." These vehicles were built with a combined air reservoir volume less than 12 times the combined volume of all service chambers. Unusually frequent applications of the air brakes could deplete the available air supply more quickly than expected. Correction: Dealers will install an additional air tank on chassis with a single rear axle. On tandem rear axle chassis, dealer will replace an existing air tank with a larger air tank.