1995, MACK RD690S CONCRETE MIXER TRUCK.(12) 1994 & (12) 1995 MACK RD690S TRUCKS. Bridge Axle Mixer Trucks, 300 HP Eng., T2080 Trans., A/C, 20,000# F/A, 44,000# R/A, 10 1/2 YD MTM Mixers w/ Bridgemaster III Axles.