CALIPER/BRAKE LOCK UP AND EXCESSIVE HEAT/BURNING/SMOKING (ABS SENSORS BURNED OUT DUE TO HEAT). MANUFACTURER (WORKHORSE) HAS APARENTLY KNOWN ABOUT IT FOR YEARS, DELAYING REMEDY PARTS, AND REFUSED TO COMPLETE "TEMPORARY" FIX ON ALL 4 WHEELS AFTER A BREAKDOWN ON AFFECTED VEHICLE. THIS CAUSES MULTIPLE BREAKDOWNS AND POTENTIALLY DANGEROUS SITUATIONS TO BOTH OCCUPANTS AND OTHERS AROUND. WE WERE "AUTHORIZED" FOR REPAIR ON ONLY 2 WHEELS. DUE TO BREAK DOWN TRIP HAD TO BE CANCELED. RV WAS LEFT FOR REPAIRS AT AN AUTHORIZED DEALER 300 MILES FROM OUR HOME. WE WENT BACK TO PICK IT UP 1 MONTH LATER AND AFTER 50 MILES, A THIRD BRAKE LOCKED UP CAUSING MOTORHOME TO START SWAYING SIDE TO SIDE AND PLACED EXCESSIVE PULL ON ENGINE TRYING TO GET TO SAFETY. BRAKES WILL LOCK UP AND STAY LOCKED UP OR DRAG WITH NO NOTICE. WE HAD TO RETUN RV TO REPAIR SHOP AGAIN FOR MORE "AUTHORIZATION" PRIOR TO ANY REPAIR, CAUSING ANOTHER TRIP CANCELATION. THIS IS OVER 300 MILES FROM OUR HOME CAUSING FURTHER UNDUE HARDSHIP. WE WERE TOLD IT WILL BE "DOUBTFULL" THEY WILL AUTHORIZE 4TH WHEEL REPAIR FORCING US AGAIN TO ABANDON DRIVING OR USING VEHICLE UNTIL PROPER PARTS ARE AVAILABLE. WE ARE CURRENTLY AWAITING A RESPONSE FROM WORKHORSE.