FLYWHEEL HOUSING GROUP 8N0422 - Caterpillar

A new 5P8744 Adapter Assembly (see Illustration 1) is used with the 5P4150 Nozzle Tester Group to test all capsule-type fuel nozzles. The new adapter gives a more positive seal when testing both direct injection and precombustion chamber nozzles on all 3400 Series Engines. With the former adapter the nozzle was held in place by the retainer threads. The new adapter holds the nozzle in place with hydraulic pressure from the pump. This hydraulic pressure gives the additional force necessary to check "leak-down rate" and VOP (Valve Opening Pressure) for direct injection nozzles on 3400 Series Engines. The former 5P4717 Adapter, which has been canceled, can still be used for precombustion chamber nozzles. The new 5P8744 Adapter Assembly and its parts are available for parts service (see Illustration 2).
Illustration 1. 5P8744 Adapter Assembly.
Illustration 2. Service parts for 5P8744 Adapter Assembly.Special Instruction Form No. FM055225 "Use Of 5P4150 Nozzle Testing Group And 8S2245 Nozzle Cleaning Kit" has been completely changed to give the procedures and specifications for capsule-type and pencil-type fuel nozzles. The new special instruction form number is SEHS7292. Also available are four new special instructions which are "summaries" of the test procedures for capsule-type and pencil-type fuel nozzles. See the chart that follows: