Usage:
NOTE: 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.
NOTE: This Program can be administered either before or after a failure. In either case the decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS8294" as the Part Number and "7755" as the Group Number. If administered before failure, use "56" as the Warranty Claim Description Code and use "T" as the SIMS Description Code. If administered after failure, use "96" as the Warranty Claim Description Code and use "Z" as the SIMS Description Code.
Termination Date
January 31, 1996Problem
The fuel-air ratio control (FARC) may not have been set on certain 924F Loaders and IT24F Tool Carriers.
Affected Product
Model & Identification Number
924F (5NN75-112, 5NN114-121, 5NN124-124, 5NN125-125)
IT24F (4NN51-70, 4NN72-78)
Parts Needed
Not applicable.
Action Required
1. Remove the valve cover and install the 1U6679 Rack Position Indicator from the 1U6680 or 9U7305 Tool Kit at #1 injector. The 8T1000 Digital Indicator should be used to obtain the rack readings.
2. Zero the indicator with the injector rack held against the injector body.
3. Disconnect the air line from the inlet manifold to the governor fuel ratio control at the fuel ratio control. The governor will only move to the fuel ratio limited rack with this line removed, not to the full rated rack.
4. Start the engine and set the machine brakes. Stall the engine at high idle against the torque converter with the transmission in third speed and read the rack value on the digital indicator. Ten seconds at stall should provide a stable reading.
5. The rack reading should be 1.0 mm less than the static fuel setting given on the engine data plate located on the valve cover. For example, the rack reading should be 5.85 mm if the data plate static fuel setting is 6.85 mm. (6.85 - 1.00 = 5.85).
6. The fuel ratio control should be adjusted using the 1U7299 and the 1U7300 Wrenches until the proper rack reading is obtained.
7. Seal the plug over the fuel ratio control adjustment screw when the proper rack reading is obtained and reconnect the air line from the inlet manifold to the fuel ratio control.
Service Claim Allowances
NOTE: This is a 1-hour job.
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.