Proper Testing For Air Intake System Leakage
The turbocharger on the dCi6 engines in Mack Freedom model chassis use an outlet adapter that cannot be checked for leakage by conventional methods. The following method can be used to investigate low power complaints or when performing similar diagnostic procedures:
- Disconnect the turbocharger inlet elbow from the intake air duct.
- Using the charge air cooler tester (Tool No. J 41473), insert the plug with the air fitting into the rubber inlet elbow and secure it with a suitable hose clamp. (See Figure 1.) Be sure to connect the safety cable in an accessible location to prevent the plug from blowing off when the system is pressurized.
- Connect the pressure regulator and gauge assembly from the test kit to the air fitting in the plug. Then connect shop air to the regulator.
- Slowly open the air regulator to apply a maximum of 9 psi to the intake system. The engine might need to be slowly rotated to prevent overlapping valves. If it is necessary to rotate the engine, close the air regulator to block the flow of air to the intake system.
- Spray a soap and water solution on the connection for the turbocharger outlet adapter to check for leaks. Also, spray the complete intake system, from the turbocharger inlet to the intake manifold gaskets, to check for leakage at those locations as well.
Engine Electronic Control Unit Flash & Reprogram
Mack has warned that before replacing an engine ECU on an E-Tech or ASET engine for any reason other than an “engine cranks but does not start” condition, the control unit must be flashed and reprogrammed without saving customer data.
All customer data must be entered manually when the process completes. The flash and reprogramming is necessary to ensure that the issue is module-related and not program-related.
Note that if the reflash fails and “Error 74” occurs, upload the verification file to V-Mac Online. Also verify that the fuses for all other control units have been removed and then attempt to reflash the engine ECU a second time. If the second reflash fails, stop and contact the company’s reliability engineering department for further instructions.
For ASET AC engines the VTG actuating system must be recalibrated for proper operation following the reflash/reprogramming procedure, or whenever parts are replaced or when certain diagnostics are performed.
Monitor the actuator during calibration to ensure that full stop-to-stop travel is achieved. A failure to calibrate the VTG actuating system could result in performance issues, or logged VTG and/or EGR codes. Perform recalibration during any of the following circumstances: Turbocharger replacement, engine ECU replacement or reprogramming, VTG actuator replacement, actuator control valve replacement, active or inactive 4-5 or 4-9 fault codes with an FMI of 7 and complaints of low boost.
Alternative Wheel Removal & Installation
Hendrickson calls for the complete removal of the tee fitting from the hubcap when removing the wheel assembly from the suspension.
Alternatively, you can remove the wheel assembly with the tee fitting still installed on the hubcaps as long as the wheel assembly is rotated so that the tee fitting is in the six o’clock position. (See Figure 2.)
With the tee fitting in this position, it is more protected from potential damage when the wheel assembly drops down onto the hub after clearing the wheel studs. If a wheel dolly is being used for the removal, the wheel must be lowered to clear the tee fitting.
Exhaust Manifold Cleaning After Engine Failure
Mack warns that metal debris from a catastrophic engine failure can become lodged in the exhaust manifold. If the debris is not removed, it eventually can dislodge and enter the turbocharger, which results in turbine wheel damage and turbocharger failure.
Inspect the exhaust manifold as follows to prevent turbocharger failure following a catastrophic engine failure.
- Remove the turbocharger and the exhaust gas regeneration (EGR) valve, if applicable.
- Remove the exhaust manifold from the engine.
- Separate the exhaust manifold sections and then inspect the inside of each. If the sections don’t separate easily, use an inspection mirror to inspect inside the manifold thoroughly through each of the six exhaust ports, as well as through the turbocharger (and EGR if applicable) mounting ports. Remove any debris present.
- With the exhaust manifold removed from the engine, inspect the cylinder head exhaust ports for damage and debris. Remove any debris and clean the affected areas.
It’s unusual for debris to be lodged in the manifold or cylinder heads to the point where it cannot be removed. Only replace the exhaust manifold if there is irremovable debris.
For ASET AC engines, perform the following checks to ensure that small pieces of debris aren’t lodged inside any of these components.
- Check the EGR valve for debris by sliding the valve actuator through its full range of travel. To do this, remove the EGR valve from the engine by holding the valve upside down and then using pliers to grasp and move the rod. If the valve actuator sticks or binds, replace the EGR valve.
- Check the variable geometry turbocharger vanes by removing the clevis pin from the turbocharger vane actuator and then move the actuator lever from stop to stop. The vanes should move freely and smoothly without binding.
If there is any indication of vanes sticking or binding, replace the turbocharger.
- Inspect the EGR cooler for debris that may be lodged on top of the hot gas inlet side fins by removing the hot side tube from the EGR cooler, then use a small dental mirror and a flashlight to inspect inside the cooler. Also check inside the hot side tube for debris. Replace the EGR cooler if you see any debris. Clean any debris found inside the hot side tube.
Height Control Valve Installation
To install Hendrickson’s Vantraax height control valve with integral dump capability, use the following steps:
- If necessary, install the height control valve bracket in the holes provided on the bottom surface of the roadside K-brace. Use the set of holes closest to the cross member. (See Figure 3.)
Orient the bracket so the triangular part of the bracket points to the rear of the suspension.
- Tighten the two bracket mounting nuts to 40 in.-lbs. to 50 in.-lbs.
- Install the height control valve on the bracket, but do not fully tighten the valve mounting nuts at this time. The valve must be rotated in steps eight and nine to attach the linkage assembly.
- Using the existing brake chamber mounting hardware, install the bottom bracket to the rear of the brake chamber mounting bracket. (See Figure 4.)
Do not sandwich the bottom bracket between the brake chamber and the brake chamber mounting bracket. Tighten the brake chamber mounting nut to 100 ft.-lbs. to 110 ft.-lbs.
- Plumb the valve. This valve features DOT push-to-connect ports for quick, easy positive connections. When making connections to the valve:
- Cut tubing squarely. A maximum 15 degree angle is allowable.
- The tube insertion depth is .81″. Make sure this tubing is free of scratches, nicks, paint, oil, undercoating, etc.
- Make sure the mating valve port is clean and debris free.
- Insert tubing into the valve until it bottoms. Push twice to verify that the tubing is inserted properly.
- Pull on the tubing to verify that it is inserted properly.
To disassemble the tubing from the height control valve, press the release collar against the valve body and pull the tubing out of the port.
- Pressurize the air system. Verify proper operation by raising the control arm approximately 20 degrees above horizontal. The air springs should inflate, but if they do not:
- Verify that the air reservoir pressure is sufficient to open the pressure protection valve.
- Check the air lines for proper part connection. If the air springs inflate properly, lower the control arm approximately 20 degrees below horizontal to verify that air flows through the valve’s exhaust port and that the air springs deflate.
- Using the height control valve, bring the suspension to its recommended 16″ ride height by raising or lowering the control arm. Ride height is defined as the distance from the suspension mounting surface to the center of the axle.
- With the suspension at ride height, install the linkage assembly between the control arm and the bottom bracket.
- If necessary, rotate the height control valve on the mounting bracket to keep the valve control arm in the center position while accommodating the full length of the linkage assembly.
- Tighten the two valve mounting nuts to a torque of 40 in.-lbs to 50 in.-lbs.
- Make sure that the ride height still measures 16″ after you have installed the linkage assembly.
Revised Exhaust Manifold
Mack revised the exhaust manifold center section used on its ASET AC engines to reduce the slip-joint clearances, which provides improved sealing of exhaust gases.
If you find exhaust leakage at the manifold slip joints, replace the manifold center section with the revised manifold with tighter slip-joint tolerance.
Fifty-one Quart Oil Pan
On January 17, 2006, Mack phased a 51-quart oil pan into production. This pan, made of 13-gauge material, replaced the 52-quart oil pan made of 14-gauge material.
As well as being the standard oil pan on ASET AI and AMI engines used in CV and CT models with ASET AI-400 engines, the 51-quart oil pan now is the standard oil pan for ASET AC-460P and AC-460E engines and also is an option for other ASET AC engine models.
Engines with the 51-quart oil pan have a total system capacity of 55 quarts.
A yellow sticker that notes the increased oil capacity is affixed to the Centri-Max filter oil fill spout to ensure that the proper amount of oil is used to fill these engines at each oil change.
The 52-quart oil pan no longer is available. When you replace an existing 52-quart oil pan with a 51-quart oil pan, the identification label must be replaced with the new “55 quart oil system capacity” label (Part No. 4MR21114). (See Figure 5.)
The 51-quart pan requires a new oil pan mounting isolator (Part No. 41GC227). The isolator grommet is made from a harder material necessary to provide increased loading on the oil pan gasket, reducing the possibility of leakage.
Countershaft Consolidation
The service replacement main box countershafts for Mack T310 series transmissions have been consolidated into one part number that covers both oil pump drive and PTO versions. (See Figure 6.)
The main box countershaft (Part No. 605KC4179) is a direct replacement for the standard version (Part No. 605KC3188), PTO version (Part No. 605KC3174) or oil pump version (Part No. 605KC4172) countershafts.
On January 16, 2006, two revised main box countershafts (Part Nos. 605KC4232 for standard and 605KC4233 for PTO versions) were implemented into production on T310 series transmissions. These revised countershafts have first and reverse gears integral with the shaft. (See Figure 7). Both countershafts include the pump drive.
Individual first and reverse countershaft gears will cease to be available for the T310 series transmission as service stock depletes. If a first or reverse countershaft gear fails on a T310 series transmission manufactured before January 16, 2006, replace it with the revised integral first and reverse gear-type countershaft.
Because of dimensional differences between the previous and the revised countershafts, you must replace the second gear when installing a revised countershaft in place of the previous countershaft.
