EDGE-CUTTING 2296599 - Caterpillar

(1LW) (14 Liter),
(5DS) (16 Liter) Truck EnginesThere have been several questions from the field about the 1998 3406E cooling system regarding the "220°F Top Tank Temperature".
The change to the "220°F Top Tank" is effective with the 1998 3406E Truck Engines, on both the 1LW (14 liter) and 5DS (16 liter) 3406E Truck Engines. The approximate temperature for FAN ON moves from 206°F to 216°F. The derate temperature is changed from 217°F to 226°F, and the shutdown temperature is now 234°F. The electronic troubleshooting guide does identify this strategy. Please refer to the new Electronic Troubleshooting Guide, RENR1328-01, PB-18, "Cooling Fan and A/C High Pressure Switch Circuit Test" (Page 145). Also, on Page 10, Illustration 3 shows the derate graph for the 3406E Truck Engines. (Do not look at Illustration 2 because it is for C-10 and C-12 Truck Engines ONLY.)
The "220°F Top Tank/Out" of engine temperature is determined by the size of the OEM cooling system. At this time, none of the OEMs have changed their cooling systems and the engines will continue to operate at the standard 210°F Top Tank specification. Load factors, ambient temperatures, and ratings may cause the cooling system to rise to the higher temperatures. The thermostats have not changed. They are still the 195°F style and are in parallel. On the 1998 3406E Engines, there is some increase in flow in the engine system due to the dual thermostats and the change in the oil cooler bonnet (going into the number 6 liner area of the block, previously into the number 4 liner area).
The main reason for changing to the 220F Top Tank capability is to satisfy the requests from OEMs. The OEMs required higher temperature levels for future cooling system packages.