2000/10/01 Caterpillar

Truck Engines:

C-15 (S/N: 6NZ26296-UP)

C-16 (S/N: 7CZ1445-UP)

Description of Change: A new Jake Brake housing is now used in the engine brake groups on these truck engines. The new housing has been changed in the area of the slave piston. The elephant's foot has been removed from the actuation pushrod and the screwdriver slot in the lash adjusting screw has been changed to a 3/8 inch nut.

Adaptable To: Table 1 identifies the engine brake group and the part numbers for the original housings and the part numbers for the new housings.

Table 1

Engine Brake Group	System Voltage	Original Part Number for the Housing	New Part Number for the Housing
148-7483, 194-4273	12	157-3493	189-5949
148-7486	24	157-3495	189-5950

The new designed housing assembly is interchangeable with the previous design but the individual components should not be interchanged or mixed. The torque on the jam nut for the adjusting screw remains unchanged at 34 N·m (25 lb ft). The lash setting for the exhaust rocker arm does not change. Refer to Table 2.

Table 2

Engine Model	Horsepower Rating	Slave Piston Lash Setting
C-15	Lower than 435 hp	0.94 mm (0.037 inch)
C-15	435 hp output and higher	0.84 mm (0.033 inch)
C-16	All engines	0.94 mm (0.037 inch)