COLLAR (OUTER) 1M4224 - Caterpillar

All Caterpillar Diesel EnginesReference: "6V2023 Flow Check Adapter Group Is Available" on Pages 3 and 4 of the March 31, 1980 Service Magazine.
Use the procedure in Special Instruction, Form No. SMHS7083 when the 6V2023 Flow Check Adapter Group is used to check injection timing. Damage to an engine can result if the adapter group is not used correctly.
The 6V2023 Flow Check Adapter Group is used to check the injection timing on all Caterpillar Diesel Engines through use of the fuel flow method.
Correct use of the 6V2023 Flow Check Adapter Group is important to prevent possible damage to an engine caused by engine run-away conditions (overspeed conditions). A seizure of an injection pump plunger can result if the 6V2018 Pin (part of the 6V2023 Flow Check Adapter Group) is extended too far before the adapter is installed into a pump. If the pin is extended too far, the reverse flow check valve will be pushed into contact with and be broken by the pump plunger. The broken parts can cause a seizure of the pump plunger. If the governor is in the "fuel-on" position and an engine is started in this condition, a run-away can result.
Add the "CAUTION" in this article to the reference articles which are shown above.