REMOVAL AND INSTALLATION







Removal steps
<<A>>
>>C<<
1.
Rocker arm shaft


2.
Adjustment screw


3.
Lock nut
<<A>>
>>C<<
4.
Unit injector
<<B>>
>>B<<
5.
O-ring
<<B>>
>>A<<
6.
O-ring


7.
Injection pump pin (Ball stud)


8.
Cylinder head

REMOVAL SERVICE POINT



<<A>> ROCKER ARM SHAFT AND UNIT INJECTOR REMOVAL


1.Remove upper toothed belt guard and cylinder head cover.

2.Loosen lock nut of adjustment screw "A" and back out screw until respective rocker arm lies against plunger spring of unit injector.
3.Remove rocker arm securing bolts 5 to 1 (from outwards to inwards) using special tool Triple square (10) wrench (MB995227) and remove rocker arm shaft.
4.Pull connector off unit injector.
5.Loosen securing bolts "B" for unit injectors using special tool Triple square (6) wrench (MB995228) and remove bolts.
6.Pull ball stud out of injector unit.

7.Insert special tool Injector puller (MB995219) into bolt holes of unit injector.
8.Turn spindle gently against unit injector. Tighten lock nut hand tight.
9.Pull unit injector upwards out of cylinder head seat with cautious taps of special tool Slide hammer (MB995218).

<<B>> O-RING REMOVAL


Lever old O-rings very carefully off unit injector using a "soft" tool. Above all ensure that burrs are not caused on the seating for the O-ring.

INSTALLATION SERVICE POINT



>>A<< O-RING INSTALLATION


note
  • Always use special tool O-ring installer A (MB995220) to fit the O-rings. There is a danger of damaging the O-rings if the sleeves are not used.
  • Ensure therefore that O-rings are assigned correctly to their respective grooves.
  • Prevent O-rings from rolling when sliding them on. The O-rings must not be twisted in their seats in unit injector.
1.Clean O-ring seating surfaces on unit injector very carefully.

2.Slide special tool O-ring installer A (MB995220) onto limit stop on unit injector.
3.Slide upper, thicker O-ring carefully onto assembly sleeve and into seat on unit injector.
4.Remove special tool.

>>B<< O-RING INSTALLATION


note
  • Always use special tool O-ring installer B (MB995221) to fit the O-rings. There is a danger of damaging the O-rings if the sleeves are not used.
  • Ensure therefore that O-rings are assigned correctly to their respective grooves.
  • Prevent O-rings from rolling when sliding them on. The O-rings must not be twisted in their seats in unit injector.
1.Clean O-ring seating surfaces on unit injector very carefully.

2.Slide special tool O-ring installer B (MB995221) onto limit stop on unit injector.
3.Slide upper, thicker O-ring carefully onto assembly sleeve and into seat on unit injector.
4.Remove special tool.

>>C<< ROCKER ARM SHAFT AND UNIT INJECTOR INSTALLATION


1.
caution
  • Each time work is performed which requires adjustment of the unit injector via adjustment screw, the adjustment screw in the rocker arm and also the unit injector ball stud must be renewed. otherwise excessive wear of the components is the result.
  • It is absolutely necessary to renew the securing bolts of the unit injector.
Before installing unit injector, check that new seals are properly seated.
note
  • New unit injectors are supplied with O-rings.
  • If old unit injector is reused, O-rings must be renewed.
  • The seals must not be twisted.
2.Oil the seals and stem of unit injector.
3.Check seat of unit injector in cylinder head for soiling or foreign objects (metal shavings/carbon deposits etc.) and clean with compressed air, if necessary.
4.Insert unit injector into cylinder head with great care.

5.Fit valve assembly device special tool Valve lever support (MB995213) with special tool Valve lever base (MB995229) on retaining frame of cylinder head as shown.
caution If the unit injector is pulled down by the securing bolts, there is a risk of the unit injector not being pulled correctly into its seat. This can result in engine running problems and starting problems. For this reason the unit injector may only be secured after it has been pushed in its seat.

6.Fit the new securing bolts and carefully screw in by hand onto stop arrow without force.

7.Now fit special tool Valve lever (MB995210) with special tool Valve lever holder (MB995230).
8.Carefully press unit injector in its seat using special tool Valve lever (MB995210) and maintain this force.
9.Carefully screw in securing bolts of unit injector by hand and without force onto stop using special tool Triple square (6) wrench (MB995228).
10.Tighten new securing bolts as follows:
Stage 1 = 3 N·m
Stage 2 = 1/4 turn (90°) further
Stage 3 = 1/2 turn (180°) further
note Renew adjustment bolts "A" and ball pins of unit injector.

11.Put rocker arm shaft in place and evenly tighten new securing bolts in the sequence 1 to 5 hand tight.
12.Then evenly tighten to 20 N·m and 90° (1/4 turn) further in the same sequence.

13.Fit the dial gauge onto the adjustment screw of the unit injector as shown.
14.Turn the crankshaft in engine direction of rotation until the roller of the rocker arm is positioned on the peak of the drive cam. Roller side "arrow A" positioned at highest point. Dial gauge "arrow B" positioned at lowest point.
15.Remove dial gauge.
16.Now turn adjustment screw into rocker arm until a firm resistance is felt (unit injector positioned at stop).

17.Turn adjustment screw 180° back off limit stop.
18.Hold adjustment screw in this position and tighten the lock nut to the specified torque of 30 N·m.
19.Push on unit injector connector and install cylinder head cover and toothed belt guard.