SEAL AS-BUFFER 1672216 - Caterpillar

3114 And 3116 Industrial, Marine, And Generator Set EnginesReference: Engine News, December 1993, Page 2; "New Fuel Filter Helps Prevent Hard Starting Due To Injector Wear" Hard starting complaints can be difficult to diagnose. However, hard starting due to worn injectors can be easily identified, as well as easily prevented. Worn injectors due to dirt in the fuel always exhibit hard starting when the engine is warm or hot. As injectors wear further, hard starting when cool or cold can also occur. However, hard starting when the engine is cold may be due to several causes other than worn injectors. If the engine re-starts well when it is warm or hot, then worn injectors are not the cause of cold starting complaints.
The Reference Article describes a new finer fuel filter with a new smaller thread size, matching filter base, and relief valve that is adaptable to most 3114 and 3116 engines (except those with "remote mounted" fuel filter locations). Since then, Caterpillar has announced several new "High Efficiency" filters that are available in both the new smaller thread size, as well as the standard thread size. This article describes filters available for 3114 and 3116 engines.
Most Caterpillar machines with 3114 and 3116 engines now have the improved "High Efficiency" 1R-0751 Fuel Filters with the smaller (7/8inch) thread size, and can be identified by the presence of the new fuel pressure relief valve located in the fuel line between the governor and the fuel filter base.
Earlier machines with 3114 and 3116 engines which use the standard 1R-0740 Fuel Filter can be easily converted, or customers can use the available "High Efficiency" fuel filters with the standard (1 inch) size thread. However, they would not have the added protection of the fuel pressure relief valve described in the Reference Article.
Caterpillar recommends the "High Efficiency" fuel filters for all Industrial, Marine, and Generator Set Engines to help prevent fuel system wear caused by dirt in the fuel. The recommended fuel filter replacement interval is 250 hours, or more often if needed.
Install fuel filter "dry", and use the hand priming pump to prime the fuel system. Never "pre-fill" the filters with fuel, as it could be contaminated and damage the fuel system.