Page 326
REPAIR INSTRUCTIONS, PART 1
381
Figure 381 — Pin-Type Valve Yoke (Non-Brake Shown)
4. For non-brake and J-Tech™-equipped
engines, place the six exhaust valve yokes
on the yoke guide pins from which they were
removed.
The exhaust valve yokes on engines equipped
with the J-Tech™ engine brake use an actuating
pin adjusting screw assembly, part Nos.
421GC41M, 421GC41AM, 421GC41BM or
421GC41CM, in place of the standard yoke
adjusting screw at the exhaust valve locations.
Make sure that the yokes with the actuator pin
assemblies are in position over the exhaust
valves.
If the actuating pin adjusting screw assemblies,
part Nos. 421GC41M or 421GC41AM, are worn,
or there are broken valve yoke guide pins or
broken rotator springs, the possibility exists that
the engine brake slave piston springs are also
broken. The slave piston springs should be
removed and inspected as outlined in service
bulletin SB-213-027, and replaced as required.
A parts kit, part No. 215SB321, that contains new
design reset screws, slave piston springs and
actuating pin adjusting screws (part No.
421GC41CM) is available through the MACK
Parts System to update the engine brake units.
However, always verify that the engine is not
already equipped with these new components.
5. For the PowerLeash™ exhaust brake, place
the exhaust yoke over the guide pin. The
adjusting screw end of the yoke goes over
the outboard exhaust valve.
382
Figure 382 — Installing Exhaust Yoke
6. After the PowerLeash™ exhaust brake valve
yokes have been installed, yoke balance
can be adjusted. Refer to “Valve Yoke,
Valve Lash and Slave Piston Adjustments”
in the ENGINE SETUP AND
ADJUSTMENTS section.
When assembling the cylinder heads, it is easier
to adjust the exhaust valve yoke balance on all
the yokes before the rocker shaft assembly is
installed.
7. On the PowerLeash™ exhaust brake valve
yokes, after adjusting the exhaust yoke lash,
lubricate the brake actuating pins with clean
engine oil and install.
1. Rocker Arm
2. Yoke Adjusting Screw
3. Jam Nut
4. Valve Yoke
5. Valve Stem
6. Yoke Guide Pin
5-111.bk Page 326 Monday, July 10, 2006 2:26 PM
To Next Page
Loading...
