BRAKESAVER CONTROL 6V4749 - Caterpillar

Caterpillar: Confidential Yellow
PSP FOR INSTALLING NEW FUEL RATIO CONTROL ON 3306 DI-TA TRUCK ENGINES PS0160 WORLDWIDE EXCEPT BRAZIL COSA SENT TO TRUCK TEPS
  The information supplied in this service letter may not be valid after the termination date of this program.   Do not perform the work outlined in this Service Letter after the termination date without first contacting your Caterpillar product analyst.
PSP FOR INSTALLING NEW FUEL RATIO CONTROL ON 3306 DITA TRUCK ENGINES, 1278, 1250, PS0160 U-22 A-20 AU-18 C-21 E-20 TT-2 Problem Most of the listed 3306 DITA (Direct Injection Turbocharged Aftercooled) Truck Engines are equipped with a 7N8622 Fuel Ratio Control Group. Complaints of slow acceleration in the 1350-1500 rpm range may be received. Slow acceleration can result from the fuel ration control causing too much delay in rack movement to the "full on" position. A new fuel ratio control is now used and available for parts service. The piston in the new control has no spring preload to overcome when any initial boost is received behind the piston. Thus, the piston can move instantly, resulting in quick rack movement to the "full on" position. Affected Models And Parts The following 3306 Truck Engines are included in this PSP if they have not been reworked and a complaint of "slow engine response" or "poor engine performance" is received. 3306 Truck Engine Serial Numbers Parts Needed 63Z1-63Z709 1 - 4W1037 Fuel Ratio Control Group 1 - 5D6539 Seal Action Requested (Parts Stock Action Required) No action is necessary unless an actual performance complaint is received. The purpose of this Program is to extend consistent support to users with actual performance complaints on eligible engines. The following inspection and replacement, if necessary, of the fuel ratio control should be done before doing other normal diagnostic work. If you receive a "slow engine response" complaint on one of the listed engines, check the following: 1. Is the identification "M-6" stamped on the block near the engine serial number plate? See left rear side of block. If so, the engine has been reworked and no further work is needed. 2. Check the part number of the fuel ratio control on the flat side of the control. Replace the control if the part number is "7N8622". If the engine needs a new control, proceed as follows: 1. Remove former control. 2. Remove boost line fitting from old control and install in new control. Tighten fitting to 16 +/- 2 N.m (12 +/- 1 lb ft). 3. Install new control group and the seal. Tighten two mounting bolts to 12 +/- 4 N.m (9 +/- 3 lb ft). 4. Operate the engine and check for oil leakage. 5. Check vehicle