Air Induction System
The air induction system must be visually inspected.
Air Induction System Inspection
Follow this procedure to inspect the Air Induction System.
- Inspect the air cleaner housing externally for damage or distortion that could allow unfiltered air to enter the engine.
Unfiltered air leakage into the induction system can cause accelerated engine wear.
- Inspect the air cleaner housing internally for end seal movement indicated by polishing where the end seal contacts the air cleaner housing. End seal movement indicates dirt may have passed the air cleaner element and entered the engine.
- Inspect the air cleaner element for holes, damaged seals, element sooting, end cap denting because of overtightening or damage during servicing.
- Inspect the air intake hoses and clamps for tightness and positioning over sealing beads.
- Inspect the chassis mounted air charge cooler and piping.
Air Induction System Pressure Test
Conduct the air induction system pressure test as follows:
- Mask off the outer diameter of the air cleaner element air inlet with duct tape and plug the air cleaner canister drain.
- Remove the air cleaner restriction indicator or tubing at the air cleaner. Install a plug to seal the opening.
- Locate the tap on the cold air discharge pipe that contains a plug. Remove the plug and connect a manually regulated air supply with a pressure gage to the tap opening. See Figure
“Regulated Air Supply”
Figure 1. Regulated Air Supply
- Apply 5–8 lb/in.2
(psi) of air pressure with regulator to pressurize the air induction system. A constant supply of air is needed to compensate for the air loss through opened intake valves.
- Coat the following areas with the soap solution and check for leaks. Leaks will cause air bubbles to form. See Figure
“Air Induction System Leakage”
- Air cleaner body surface around the outlet pipe.
- Air cleaner outlet pipe to air cleaner body junction.
- All clamped hose and gasket connections between air cleaner outlet and intake manifold valve/valve cover. This includes the connections at the turbocharger.
- Surface of all air induction piping and hoses between air cleaner and intake manifold/valve cover.
- When applicable, the air compressor air inlet piping from the air cleaner tube to and including the fitting and the gasket.
- Piping to the air charge cooler.
- No leakage is permitted between the air cleaner and the turbocharger (suction side). If leakage at the joints is detected, tighten the hose clamps. If leakage persists, remove the parts to determine the cause. Replace the parts as necessary, using the latest clamps and torques specified. Retest the corrected area.
Figure 2. Air Induction System Leakage
Any leaks found in the air induction system could have allowed dirt to enter the engine. Dirt entering the engine can cause piston rings to wear abnormally or break (causing high oil consumption), excessive blue smoke, turbocharger compressor wheel pitting and erosion.
|Series 40E Troubleshooting Manual – 6SE241|
|Generated on 10-13-2008|