Revised Oil Change Intervals
Mack revised the recommended oil change intervals for its ASET AC-460P and AC-460E engines. To keep engine wear to a minimum, engine oil and filters need to be changed at regular intervals before soot levels exceed 5% and oils that meet the company specification EO-N Premium Plus 03 high-performance diesel engine oil be used with approved oil filters.
Mack recommends oil analysis programs for monitoring the overall condition of the oil and for determining soot levels. The company approved two soot measurement methods: Thermogravimetric analysis and the light extraction method.
Figure 1 displays the revised specified oil and filter change interval for all ASET AC-460P and AC-460E engines.
Replacing Electronic Control Units
Unlike previous generations of electronic control units (ECU) where antilock braking system (ABS) units could be switched out, Bendix EC-60 Advanced ECUs are vehicle specific. Because the company customizes the stability system for the actual vehicle configuration and its sensors, the VIN is required to order replacement ECUs.
Bendix Advanced ABS ECUs intervene based on feedback from expected sensor locations and orientations. Install sensors in their original position and orientation on the vehicle, and recalibrate the sensors after related maintenance work.
Maintenance procedures that require recalibration are steering wheel replacement, steering angle sensor or yaw rate/lateral acceleration sensor replacement, any maintenance that involves opening the connector hub from the steering angle sensor to the column, maintenance or repair work on the steering linkage, steering gear or other related mechanism replacement, wheel alignment or wheel track adjustment and accident repairs.
Tube Replacement
On all Caterpillar 3126 model engines, use the 164-0201 Tube As to replace the 135-5980 Tube As.
The company warns that in extreme operating conditions, oil pressure pulses may cause the 135-5980 Tube As to crack. The same pressure pulses also may cause the 167-1709 Pressure Sensor Gp to fail, in which case a 164 diagnostic code will be logged in the engine control module.
A failed sensor may cause an engine shutdown or cause the engine to run erratically. If the crossover tubes or engine oil pressure sensor needs to be replaced, first remove the six 135-5980 Tube As, the six 113-6135 fittings and the 167-1709 pressure sensor. Next, install six new 16400201 Tube As, six 148-0876 fittings and a new 167-1709 Pressure Sensor Gp.
Service Replacement Suspension Crossmember
Mack warned that on its MR and LE model chassis equipped with a Telma driveline retarder, cracks may develop in the center section of the suspension crossmember in the vicinity of the torque rod mounting brackets. (See Figure 2.) If a crack develops, a service replacement crossmember is available.
To determine the replacement crossmember’s part number, refer to the chassis builder’s records for the original crossmember part number. Then, consult the cross-reference chart to obtain the replacement part number.
Water Temperature Regulator
Caterpillar has a new water temperature regulator available for its C9 engine.
The new regulator improves the strength of the cup retainer sleeve and a redundant air vent in the thermostat housing eliminates the jiggle pin.
When replacing the 115-4223 water temperature regulator, be sure to use the new 284-5421 regulator.
