When performing a pre-trip inspection on a doubles or triples combination, what must be checked at the converter dolly?

THE CONVERTER DOLLY is the critical connecting device between trailers in a doubles or triples combination. It converts a semitrailer (which has a kingpin) into a 'full trailer' that can be pulled by another trailer. INSPECTION ITEMS: PINTLE HOOK: The hook that connects the dolly drawbar to the first trailer's pintle ring; must be latched and the safety clasp engaged; a failed pintle hook separates the rear of the combination; FIFTH WHEEL ON DOLLY: Connects the second trailer's kingpin to the dolly; inspect the same as any fifth wheel (locking jaws, mounting bolts, plate condition, kingpin engagement); DRAWBAR (TONGUE): The A-frame structure connecting the pintle to the fifth wheel; check for cracks, bending, or damage; SAFETY CHAINS: Required as backup if the pintle connection fails; must be crossed under the drawbar and have proper length (enough slack for turns but not dragging); LANDING LEGS: Some dollies have small landing legs for support when parked; verify they are retracted and secured; AIR AND ELECTRICAL: Verify glad hands (air connections) are properly coupled and sealed; check electrical connector to confirm lights will function; verify both service and emergency lines connected correctly; BRAKE FUNCTION: Apply trailer brakes and observe for pressure drop indication on gauges; check for air leaks around the dolly connections.