MOVING VERY SLOWLY DOWNHILL ON A SNOW-COVERED DRIVEWAY. DEPRESSED BRAKE PEDAL, BUT ABS FAILED TO ENGAGE. BRAKES LOCKED-UP INSTANTLY, CAUSING AN APPROXIMATELY 200FT SLIDE, HITTING UTILITY POLE AND GUARD RAIL. ABOUT ONE WEEK LATER, BRAKES LOCKED AGAIN (ABS FAILED TO ENGAGE), BUT I WAS READY FOR IT AND IMMEDIATELY LET OFF AND REAPPLIED PRESSURE. THIS TIME ABS DID ENGAGE. I HAVE SINCE TESTED THE BRAKES ON SLICK SURFACES IN SAFE ZONES. ONLY THREE TIMES DID ABS FAIL, AND THE TWO TIMES THAT I LET OFF AND RE-APPLIED THE BRAKES, THE ABS ENGAGED AT THAT POINT IN TIME. EACH TIME THE ABS FAILED, IT WAS WHILE MOVING DOWNHILL. THE ISSUE FOR ME IS THAT I DO NOT KNOW HOW TO REACT WHEN BRAKING IN CRITICAL SITUATIONS: DO I PUMP THE BRAKES AS FOR W/O ABS, OR STEADILY HOLD BRAKES AS ONE WOULD WITH FUNCTIONING ABS. I TOOK THE VEHICLE (2007 TOYOTA TACOMA) TO DEALER, BUT THEY SAID BRAKES LOOKED OK. *TR