COVER GP-FRONT HOUSING 2P6529 - Caterpillar

Caterpillar Diesel EnginesSUPPLEMENT: 05/14/80ENGINE NEWS, APRIL 9, 1980, PAGE 1.In the article "6V2023 Flow Check Adapter Group Is Available," the first sentence is not correct. Change the sentence to "The new 6V2023 Flow Check Adapter Group is available to check injection timing on all Caterpillar Diesel Engines through the use of the fuel flow method."
--------------- END SUPPLEMENT ---------------The new 6V2023 Flow Check Adapter Group is available to check the fuel flow rate of all Caterpillar Diesel Engines on the Fuel Injection Test Bench.
Some direct injection engines use a reverse flow check valve on the plunger and barrel assemblies in the fuel injection pumps. This is to prevent secondary fuel injection. These reverse flow check valves operate at 100 psi (690 kPa) in the normal flow direction. The reverse flow valves operate at 1000 psi (6900 kPa) in the opposite flow direction.
A pressure of 15 psi (105 kPa) is used for flow timing, but this is not enough pressure to open either valve. The 6V2023 Flow Check Adapter Group can be used to open the reverse flow check valve and permit flow timing checks.
An injection line with a pin in one end was released for use in flow timing checks.
A short time after the reverse flow check valves were first used in direct injection 3406 Engines, the length of the check valve bonnet was changed. Two pin lengths were then needed to open the check valves. The 5P3564 Flow Check Assembly, which has a pin at each end, was released for use on both bonnet lengths. The 5P3565 and 5P3566 Flow Check Assemblies were released for use with the Fuel Injection Test Bench. Each assembly has only one pin.
Because of tolerances and additional applications of the reverse flow check valves, the use of many pins of different lengths, which is necessary, is not practical.
The 6V2023 Flow Check Adapter Group has a variable length pin. Also, the pin can be removed to use the 6V2023 Flow Check Adapter Group for flow timing checks on engines which have fuel injection pumps without reverse flow check valves.
ADAPTABLE TO: The 6V2023 Flow Check Adapter Group is adaptable to all Caterpillar Diesel Engines. This new 6V2023 Flow Check Adapter Group is a replacement for 5P3564, 5P3565, and 5P3566 Flow Check Assemblies, which have been canceled. This flow check adapter group can be used instead of the 7M1999 Tube Assembly for flow timing checks on engines which use fuel injection pumps without reverse flow check valves.
Assembly And Installation Of The 6V2023 Flow Check Adapter Group
First, assemble the 6V2023 Flow Check Adapter Group as per the illustration.
Components of the 6V2023 Flow Check Adapter Group.For use on precombustion and direct injection engines without reverse flow check valves, remove the 6V2018 Pin. Next, put the 6F0612 Nut (jam nut) at the top of the threads and push the 6L3921 Washer against it. Tighten, by hand, the 6V2020 Adapter against the 6F0612 Nut and 6L3921 Washer. Install the flow check group on the desired pump bonnet and tighten the