Procedure To Torque Camshaft Gears
For CAT engines 3406E, C-15, C-16 and C-18, follow the ensuing torque sequence to avoid premature wear of the No. 1 camshaft bearing.
Lightly lubricate the O-ring seal on the outside of the sealing plate of the camshaft with a 50/50 mixture of 8T-2998 lubricant and clean engine oil.
Next, apply 9S-3263 Thread Lock Compound to the three bolts for the sealing plate of the camshaft. Tighten the three sealing plate bolts on the camshaft to the following torque: 9 +/- 2 lb.-ft.
Now, tighten the camshaft bolts in the following sequence (See Figure 1): 1, 4, 2, 5, 3, 6, 1, 4. Torque should be 177 +/- 30 lb.-ft.
New Fuel Pressure Regulators now Available
For CAT C7 and C9 engines, a 90 micron screen has been added between the check valve and the regulator valve within the pressure regulator to increase the functionality.
The 294-8620 Regulator is a direct replacement for the 229-8870 Regulator. The 294-8621 Regulator is a direct replacement for the 229-8871 Regulator.
Updated Intake Valve Response Test Available
Applicable to its C11, C13 and C15 engines, Caterpillar has updated the test for the response of intake valve actuators. The updated information is intended to help technicians determine the cause of diagnostic codes for intake valve actuators and the intake valve actuation warm-up solenoid.
Improved Support For Precooler
Caterpillar has announced the availability of an improved support bracket now used for the precooler on its C15 engine. The 238-4438 support has greater strength because it has been heat treated. It is identifiable because it is stamped “H.”
Revised Fan Drive Mounting Nut
Mack implemented a revised fan drive mounting nut (Part No. 190AM5) into production on CXP and CTP models equipped with the Behr electronically modulated fan drives. Tie-in dates were October 9, 2006, for CTP models and October 24, 2006, for CXP models.
When servicing a Behr fan drive on a CXP or CTP model, always use the most current mounting nut. Tightening torque specification for this mounting nut is 17 lb.-ft. to 20 lb.-ft.
Interruption Of Daytime Running Light Operation
Mack warned that on its CXP and CTP model chassis, it’s possible that operation of the daytime running lights (DRL) could be interrupted by certain CB radio frequencies.
In order to eliminate this problem, the company has developed a revised DRL module (Part No. 116MO39A).
Air Intake Grill Loosening
As a result of dimensional variations in the hood opening for the air intake grille on Mack CV model chassis, the retaining clips may not hold the grille in place. The grille may become loose and fall from the hood. Should this occur, the grille should be secured with 3M two-sided tape (3M Part No. 06386) or equivalent.
Install the grille as follows:
- On the backside of the grille, clean the area of the grille between the two retaining clips with alcohol.
- Apply a 6″ piece of two-sided tape to the grille. (See Figure 2.)
- Use alcohol to clean the area on the edge of the grille opening in the hood where the tape will contact.
- Install the grille into the opening and firmly press until the retaining clips snap into place.
Revised Exhaust Manifold
A revision has been made to the exhaust manifold used on Mack ASET AI and AMI engines, whereby the slip-joint clearances have been reduced to provide improved sealing of exhaust gases. (See Figure 3.)
If you encounter exhaust leakage at the manifold slip joints, the three manifold sections should be replaced with the revised manifold sections having the tighter slip-joint tolerance.
