ENGINE BRAKES Wacobs vesicle Model 430 Died! Equipment Company . Engines Technical Data Sheet BASIC OPERATION Jacobs Model 430 is designed All Jacobs Engine Brakes contain Normal injector rocker motion specifically for use on Cummins diesel engines. The standard kit for the Model 430 Jake Brake® in- cludes all attaching components and in-cab controls needad for installation. Certain vehicle configu- rations and vehicles equipped with automatic transmissions require special adapter kits. Your author- ized Jacobs representative should be contacted to determine the Proper Engine Brake model and, if needed, adapter kit for your vehicle. @IODEL 430 FOR CUMMINS 88NT ENGINES, four primary components: the Solenoid Valve (1), the Control Valve (2) the Master Piston (3), and the Slave Piston (4). When activated, the Solenoid Valve introduces engine oil (low pressure) to the brake housing. ‘The Control Valve is unseated and allows oll o flow to the Master Piston which is then moved down against the injector rocker adjusting screw. ‘causes the master piston to move up, creating high oll pressure. The high pressure, which is maintained by the control valve, forces down the slave piston, which opens the exhaust valve. tis this precisely timed opening of the engine exhaust valve that develops Jake Brake retarding power.ENGINE BRAKE APPLICATIONS GUIDE FOR NH/NT CUMMINS ENGINES CURRENT BRAKE EARLY MODELS BRAKE MODELS ENGINE TYPE 425 | #9 | se || 20 [258] 30 [30 400 oe solar] eo NH Series 5 1/8 Bore 2 Tt ‘Small Cam NH Single Entry Turbo ‘Smail Cam tl ‘Single Entry Turbo Divided Entry Turbo Big Cam 1 ‘Single Entry Turbo Divided Entry Turbo Big Cam tt ‘Single Entry Turbo Divided Entry Turbo NTC 475 Twin Turbo(MVT) . Big Cam Ill * (Some 8.C. lil are MVT) ‘Single Entry Turbo . e . Divided Entry Turbo : Cc = z Cam V ingle Entry Turbo = < Divided Entry Turbo CPL 0734(MVT) Divided Entry Turbo CPL 0795 (MVT) ‘New Big Cam IV Flxed Timing ‘CPL 0832 CPL O76 CPL OTST. New Big Cam IV Step Timing Controt ‘CPL 0806 CPL 0821 CPL 0833 a CPL Fixed Timing —CPL 0898 Get ogao #90 FT Step Timing ~CPL 0627" CPL o9t0 490 STC CPL 1185 INOTE: THE MODEL 448 HAS BEEN UPGRADED TO THE MODEL 400H. SEE SERVICE LETTER NUMBER 237, 4 “s THE JACOBS MODEL 425 ENGINE BRAKE IS NOT APPROVED FOR ENGINES WITH MVT (MECHANICAL VARIABLE TIMING) OR 88NT ENGINES. * THE MODEL 430 GAN ONLY BE USED ON 88NT ENGINES * SLAVE PISTON SETTINGS FOR THE VARIOUS JAKE BRAKE MODELS AND ENGINE BRAKE APPLICA- TIONS WILL VARY AND ARE DEPENDANT ON: 1. CPL NUMBER: 2. INJECTOR TIMING 3, TURBOCHARGER CONFIGURATION 4, BIG CAM IDENTIFICATION * REFER TO THE JAKE BRAKE INSTALLATION MANUAL FOR THE SPECIFIC ENGINE BRAKE MODEL FOR ‘SLAVE PISTON ADJUSTMENT INFORMATION Jacobs* and Jake Brake® are registered trademarks of The Jacobs Manufacturing Compary. Form 3122 10M HP (©1987, 1988 The Jacobs Manufacturing Company Printed in U.S.A. aves