1999 GMC GMC Truck

THREE PROBLEMS - INCIDENT DATE NOT EXACT FOR ALL PROBLEMS.1) HAD VEHICLE ACCELERATE IN NEARLY WIDE-OPEN THROTTLE POSITION WHILE BRAKING AT A STOPLIGHT IN HEAVY TRAFFIC. AVOIDED ACCIDENT BY SHIFTING TRUCK INTO REVERSE AND FORWARD SEVERAL TIMES BEFORE I FINALLY WAS ABLE TO TURN OFF ENGINE. HAD TRUCK TOWED TO DEALERSHIP WHERE THE THROTTLE BODY WAS REPLACED. SINCE THAT TIME I HAVE HAD THROTTLE STICK CLOSED. I CONTACTED DEALERSHIP AND WAS TOLD CARBON DEPOSIT WAS CAUSING PROBLEM AND THEY WOULD CLEAN FOR $100.00. I PULLED HOSE FROM BODY AND CLEANED WITH CARBURETOR CLEANER, WHICH SOLVED PROBLEM FOR PRESENT. SHOULD GMC FIX THIS PROBLEM? 2) PARKING BRAKE WORE PREMATURELY. DEALER WANTS $300.00 TO REPLACE. I FEEL THIS IS A PROBLEM EXPERIENCED BY MANY OWNERS AND SHOULD BE CORRECTED BY GMC. 3) HAVE LOUD ENGINE CLACKING NOISE EVERY TIME VEHICLE IS STARTED AFTER SITTING OVER ONE HOUR. DEALERSHIP INFORMED THAT ENGINE OIL PASSAGES WERE NOT DRILLED LARGE ENOUGH AND THAT NO FIX AVAILABLE FOR PROBLEM. I BELIEVE THAT ENGINE FAILURE WILL OCCUR SOMETIME IN THE FUTURE. DOES GMC HAVE A SOLUTION FOR THIS PROBLEM? I KNOW MANY OWNERS ARE EXPERIENCING THE SAME PROBLEM.*AK