Mack MP7 - Page 87

Page 76
TROUBLESHOOTING
3. Install the appropriate lifting tool, 85109050
(MP7), 85109250 (MP8) or 85109035
(MP10), on the rocker arm assembly.
Loosen the rocker arm shaft uniformly
across the complete shaft. Remove the
rocker arm assembly.
4. Remove the unit injectors and clean the
copper sleeves if necessary.
5. Install an adapter, J 47363, in each of the
unit injector ports.
6. Refit the rocker arm assembly to the engine.
7. Install the PowerLeash™ control valve and
oil tube between the valve and the rocker
arm shaft as follows:
앫 Lubricate and assemble the seals on
each end of the oil tube.
앫 Insert the larger end of the oil tube in
the rocker shaft.
앫 Make sure the oil seal is in place at the
bottom of the valve assembly.
앫 Position the valve assembly on the
mounting plate and insert the free end
of the oil tube.
앫 Using a torque wrench, tighten the
attaching screws according to
specification.
62
Figure 62 — Engine Brake Control Valve Oil Tube
Orientation (MP7 Only)
8. Connect a remote starter switch to the
starter.
Do not run the starter motor for longer than
15 seconds at a time. Wait 60 seconds before
trying again.
9. Connect the compression gauge, J 6692-B,
to the adapter on the first cylinder. Crank the
engine with the remote starter switch until
the needle on the compression gauge stops
moving (maximum compression). Record
and repeat for all remaining cylinders.
10. Remove the screws for the PowerLeash™
control valve.
11. Remove the control valve and the oil tube
between the valve and the rocker arm shaft.
12. Install the lifting tool, 85109050 (MP7),
85109250 (MP8) or 85109035 (MP10), on
the rocker arm assembly. Loosen the rocker
arm shaft uniformly across the complete
shaft. Remove the rocker arm shaft
assembly.
13. Remove the J 47363 adapters from all of the
cylinders.
14. Install the unit injectors using new O-rings
and new sealing washers.
15. Connect the wiring harness to the unit
injectors.
16. Carefully lower the rocker arm shaft
assembly onto the head.
17. Remove the lifting tool from the rocker arm
shaft.
It is very important to tighten the rocker arm shaft
assembly uniformly across the complete shaft.
Tightening unevenly can cause damage to the
rocker arm shaft assembly.
18. Tighten the rocker arm shaft screws in the
sequence specified.
1. Control Valve
2. Oil Tube
3. Rocker Arm Shaft