HOSE-AIR 3984358 - Caterpillar

3408 And 3412 Industrial And Marine Engines;
3406 And 3408 Truck EnginesSUPPLEMENT: 03/01/82SERVICE MAGAZINE, NOVEMBER 17, 1980, PAGE 2.In the article "Check For Correct Spring Retainer On Oil Pump Bypass Valve When Oil Pan Is Removed," change the subtitle to "All 3406, 3408 and 3412 Engines."--------------- END SUPPLEMENT ---------------A 1N3246 Retainer is used to hold the spring in the oil pump bypass valve for 3406, 3408 and 3412 Industrial and Marine Engines, and 3406 and 3408 Truck Engines.
Any time an oil pan is removed from one of these engines, check to make sure a 1N3246 Retainer is used to hold the spring. The part number is on the retainer.
Formerly, a 4N522 Retainer, which is now canceled, was used. It was possible for the 4N522 Retainer to break. A broken retainer will cause the oil pump bypass valve to open and it will not close. With the bypass valve open, not enough oil will flow through the engine to give good lubrication.