Regular maintenance consisting of the tension of the compressor drivebelt and security of all the hose connections, the drivebelt has a deflection of 0.6 in (12.7 mm) at its longest run, to adjust the drivebelt, the mounting and adjustment bolt must be slackened, if the drivebelt breaks, the anti-backfire valve must be renewed. The compressor is of the lubricant sealed type and will need to be replaced if faulty. The diverter valve is located on the engine compartment rear bulkhead and the anti-backfire valve (flame trap) is attached to the air manifold. To check the anti-backfire valve: disconnect the discharge hose on the diverter valve, suck the discharge hose and check if there is any leakage, if leaking, the anti-backfire valve should be renewed. For the Diverter Valve, Unplug the discharge hose and plug it as the preventative measure, check if the outlet is blowing air when the engine is idling, do not block the outlet at high speeds, which will damage the compressor if the Diverter Valve is defective, must renew when it is defective. Excessive CO readings suggest a bad catalytic converter, which should be renewed as an item.