AT THE TIME OF THE INCIDENT, EE WAS INSPECTING THE ENGINE COMPARTMENT OF A SKID STEER FOR COOLANT LEAKS. TO GAIN ACCESS TO THE ENGINE, EE RAISED THE RADIATOR/OIL COOLER ASSEMBLY & LOCKED IT IN AN OPEN POSITION. AFTER FIXING THE LEAK, THE SUPPORT CAME LOOSE FROM ITS MOUNTING, ALLOWING THE RADIATOR ASSEMBLY TO FALL, PINCHING EE'S LT.FOREARM BETWEEN THE ASSEMBLY & THE SKID FRAME.