1990 Ford Bronco 4.9L MT Thermactor Air Pump & Check Valve Diagram (A13526-A)

This document is a Ford factory-style line drawing (illustration reference number A13526-A) showing the layout of the Thermactor secondary air injection (emissions) system on an engine, uploaded as applying to a 1990 Ford Bronco 4.9L with manual transmission. The perspective view shows the engine with its intake manifold and accessory drive area, with an arrow indicating 'FRONT OF ENGINE' for orientation. Four callouts identify the emissions components and their locations: two CHECK VALVES (one at the upper right rear of the engine near a hose connection with a clamp, and one at the left side on a hose running forward along the engine), the COMBINATION AIR CONTROL VALVE mounted at the rear/side of the engine where several air hoses join, and the belt-driven AIR PUMP mounted low at the front of the engine. The routing of the air supply hoses between the air pump, combination air control valve, and the two check valves is depicted graphically. A reader can use this diagram to identify each secondary air (Thermactor) component, verify correct hose routing, and locate the check valves and combination valve for inspection or replacement.