Disassemble/assemble compressor

AR13.30-B-5511D

Disassemble/assemble compressor

13.05.2020

Engine

372 in model 384, 386

Engine

372 in model 384

Engine

372 in model 682

Engine

376 in model 384, 386

Engine

377 in model 684

Engine

386 in model 684

1

Connecting rod bolt

2

Connecting rod cap

3

Sleeves

4

Connecting rod nut

5

Connecting rod

6

Connecting rod bushing

7

Lock-ring

8

Piston pin

9

Piston

10

Rings

11

Cylinder

12

Discharge (exhaust) valve

13

Intake valve

14

Gasket

15

Head and cylinder set screw

16

Discharge (exhaust) valve nut

16a

Discharge valve pre-assembly nut

17

Cylinder head

18

Seal ring

19

Connector

20

Clamp

21

Hose

22

Engine block

23

Camshaft

A

Entrance of air

B

Air vent



Disassemble

 Warning

Risk of accident from vehicle starting off by itself when engine running. Risk of injury (bruises and burns) resulting from working on the engine while it is being started or when it is running.

Secure vehicle to prevent it from starting off by itself. Wear closed and snug-fitting work clothes. Do not touch hot or rotating parts.

AS00.00-Z-0005-01A

1

Turn off the main switch or disconnect the negative cable from the battery

 Loosen the screw of the negative cable on the stringer, avoid loosening the battery terminals.

2.1

Tilt the hood and lock it with the safety rod

Vehicles with cab 384.0, 386.0, 694.0, 695.0.

Opening engine hood, moving to upright position and closing.

AR88.40-B-1000A

2.2

Remove the engine hood inside the cab, releasing the side clamps

.

2.3

Open the front hood of the cabin

For vehicles with 688.1 chassis, push the locking lever under the dashboard, on the left-hand side, and lift the hood.

2.4

Tilt the cabin

Vehicles with cab 682, 693.

Tilt cab to repair position, tilt back.

AR60.80-B-0010A

3

Loosen the clamps (20) and remove the hose (21)

4

Loosen the tubing at the air outlet (B) from the compressor head (17)

5

Loosen the screws (15) and remove the compressor head (17)

6

Remove the compressor cylinder (11)

7

Remove the locking rings (7) and remove the piston (9)

8

Loosen the nuts (4), remove the connecting rod (5) with the cap (2) and the sleeves (3)

 Mark the sleeves (3) against the connecting rod (5) and the cap (2).

 When removing the connecting rod (5), make sure that the sleeves (3) or the connecting rod cap (2) do not fall on the crankcase.

9

Remove the rings (10) from the piston (9)

 Use special pliers.

 Pliers

*000589373700

10

Repair the compressor head (17)

Disassemble/assemble compressor cylinder head

AR13.30-B-5511-04A

 Apply the prescribed torques: Engines 372.9, 374.9, 376.9.

 .Pre-assembly of the air compressor (MB) outlet valve

*BA13.30-B-1004-01A

 .Air compressor outlet valve (MB)

*BA13.30-B-1003-01A

 .Air compressor (MB) intake valve

*BA13.30-B-1002-01A

 Slotted nut wrench

*352589030700

11

Rework the compressor cylinder (11)

 Measure the bore at the horizontal and vertical positions and at three different points along the cylinder; if the wear is less than 0.03 mm, burnishing is sufficient to restore the surface. If the wear exceeds 0.03 mm, the cylinder should be burnished to the Normal I or Normal II dimensions, or replaced.

.Cylinder (air compressor MB 94 mm)

*BE13.30-B-1001-01A

.Clearance between the piston and the cylinder

*BE13.30-B-1013-01A

12

inspect the connecting rod bushing (6)

 Check the connecting rod bushing (6); if necessary, replace it and grind it per the relevant dimensions:

.Clearance between the connecting rod bushing ad the piston pin

*BE13.30-B-1007-01A

.Assembly interference of the connecting rod bushing

*BE13.30-B-1008-01A

.Housing diameter for the piston pin

*BE13.30-B-1009-01A

.Connecting rod bushing

*BE13.30-B-1004-01A

.Sleeve housing bore at the connecting rod foot

*BE13.30-B-1003-01A

.Piston pin diameter

*BE13.30-B-1010-01A

13

Inspect the connecting rod sleeves (3) of the compressor and the neck of the valve camshaft

 Fit the non-slotted sleeve on the connecting rod, and the slotted sleeve on the connecting rod cap.

 Fit the connecting rod cap and tighten the nuts at the recommended torque.

 With the aid of measuring tools, check the measurements:

 .Connecting rod cap bolt (MB air compressor)

*BA13.30-B-1005-01A

.Diameter of bearing shells housing in connecting rod head

*BE13.30-B-1002-01A

.Connecting rod clearance on the camshaft neck

*BE13.30-B-1006-01A

.Air compressor drive journal diameter

*BE05.20-B-1010-04B

.Connecting rod length - measured from the bearing shell seat center line to the bushing seat center line

*BE13.30-B-1005-01A

 Dial gage

*001589532100

14

Inspect the piston (9) and rings (10)

 Carefully remove the coal residues from the piston channels and inspect them for damage and wear.

 Inspect the rings for damage or wear.

.Height of the channels for the segment ring

*BE13.30-B-1015-01A

.Radial play between the pin and the piston

*BE13.30-B-1014-01A

.Thickness of the segment rings

*BE13.30-B-1016-01A

.Side clearance of the rings on the piston channels

*BE13.30-B-1012-01A

.Clearance between the piston ring ends

*BE13.30-B-1011-01A



Assemble

15

Turn the engine until the neck of the connecting rod on the camshaft (23) reaches the top dead center (TDC) and mount the connecting rod (5)

 Position the connecting rod (5) with the sleeves (3) on the camshaft and tighten the nuts.

 Assembly: When installing the connecting rod (5), make sure that the sleeves (3) or the connecting rod cap (2) do not fall on the crankcase.

 .Connecting rod cap bolt (MB air compressor)

*BA13.30-B-1005-01A

16

Install the piston (9) on the connecting rod (5)

 Position the piston (9) on the connecting rod (5) and mount the pin (8).

 Mount the lock rings (7) on the piston (9).

17

Install the cylinder (11) on the piston (9)

 Apply sealing mass to the contact face of the cylinder (11) with the block (22).

 Lubricate the rings (3) and piston (9) with motor oil, positioning the rings so that their openings are displaced 120° from each other.

 Compress the rings with a compressor belt and mount the cylinder.

Sealant Loctite 574, 50 ml

*BR00.45-Z-1009-01A

 Tensioning strap

*000589383100

18

Determine the position of the piston (9)

Remove/install compressor piston rings
.

AR13.30-B-5511-01A

.Piston protrusion relative to the upper f the cylinder at the PMS without the head gasket

*BE13.30-B-1017-01A

 Dial indicator holder

*343589004000

 Dial gage

*001589532100

19

Mount the head (17) with the gasket (14)

 Remove the screws used to determine the piston protrusion.

 Tighten the head (17) and cylinder (11) fastening screws.

 .Air compressor (MB) head and cylinder to engine block

*BA13.30-B-1001-01A

20

Install the air intake (A) and vent (B) lines on the head

 Apply a new sealing ring. Check the clamps and the hose; if necessary, replace them

Test values for the valves camshaft

Number

Designation

Engine 372.9, 376.9 - M 366 G and LAG gas-fired, 376.9 - OM 366 naturally aspirated

Engine 372.9, 376.9, 386.9 - OM 366 A/LA

BE05.20-B-1010-04B

Air compressor drive journal diameter

Normal

mm

31,984 ... 32,000

31,984 ... 32,000

Normal 1

mm

31,884 ... 31,900

31,884 ... 31,900

Repair I

mm

31,734 ... 31,750

31,734 ... 31,750

Repair II

mm

31,484 - 31,500

31,484 ... 31,500

Repair III

mm

31,234 ... 31,250

31,234 ... 31,250

Compressor

Number

Designation

Engine 374.9, 376.9

BE13.30-B-1001-01A

Cylinder (air compressor MB 94 mm)

Cylinder diameter

Normal

N - 9

mm

93,985...93,995

N - 0

mm

93,995...94,005

N - 1

mm

94,005...94,015

Normal I

NI - 9

mm

94,060...94,070

NI - 0

mm

94,070...94,080

NI - 1

mm

94,080...94,090

Normal II

NII - 9

mm

94,110...94,120

NII - 0

mm

94,120...94,130

NII - 1

mm

94,140...94,150

Normal

N - 9

mm

93,920

N - 0

mm

93,930

N - 1

mm

93,940

Normal I

NI - 9

mm

93,995

NI - 0

mm

94,005

NI - 1

mm

94,015

Normal II

NII - 9

mm

94,045

NII - 0

mm

94,055

NII - 1

mm

94,065

Compressor

Number

Designation

Engine 374.9, 376.9

BE13.30-B-1002-01A

Diameter of bearing shells housing in connecting rod head

mm

35,000...35,016

Compressor

Number

Designation

Engine 374.9, 376.9

BE13.30-B-1003-01A

Sleeve housing bore at the connecting rod foot

mm

19,000...19,021

Compressor

Number

Designation

Engine 374.9, 376.9

BE13.30-B-1004-01A

Connecting rod bushing

External diameter

mm

19,035...19,048

Inner diameter (finishing)

mm

16,025...16,035

Compressor

Number

Designation

Engine 374.9, 376.9

BE13.30-B-1005-01A

Connecting rod length - measured from the bearing shell seat center line to the bushing seat center line

mm

96,950...97,000

Compressor

Number

Designation

Engine 374.9, 376.9

BE13.30-B-1006-01A

Connecting rod clearance on the camshaft neck

Axial

mm

0,065...0,317

radial

mm

0,020...0,066

Compressor

Number

Designation

Engine 374.9, 376.9

BE13.30-B-1007-01A

Clearance between the connecting rod bushing ad the piston pin

mm

0,010...0,023

Compressor

Number

Designation

Engine 374.9, 376.9

BE13.30-B-1008-01A

Assembly interference of the connecting rod bushing

mm

0,014...0,048

Compressor

Number

Designation

Engine 374.9, 376.9

BE13.30-B-1009-01A

Housing diameter for the piston pin

mm

16,018...16,022

Compressor

Number

Designation

Engine 374.9, 376.9

BE13.30-B-1010-01A

Piston pin diameter

mm

16,012...16,015

Compressor

Number

Designation

Engine 374.9, 376.9

BE13.30-B-1011-01A

Clearance between the piston ring ends

mm

0,25...0,40

Compressor

Number

Designation

Engine 374.9, 376.9

BE13.30-B-1012-01A

Side clearance of the rings on the piston channels

mm

0,020...0,055

Compressor

Number

Designation

Engine 374.9, 376.9

BE13.30-B-1013-01A

Clearance between the piston and the cylinder

mm

0,068...0,092

Compressor

Number

Designation

Engine 374.9, 376.9

BE13.30-B-1014-01A

Radial play between the pin and the piston

mm

0,003...0,010

Compressor

Number

Designation

Engine 374.9, 376.9

BE13.30-B-1015-01A

Height of the channels for the segment ring

mm

2,510...2,530

Compressor

Number

Designation

Engine 374.9, 376.9

BE13.30-B-1016-01A

Thickness of the segment rings

mm

2,475...2,490

Compressor

Number

Designation

Engine 374.9, 376.9

BE13.30-B-1017-01A

Piston protrusion relative to the upper f the cylinder at the PMS without the head gasket

Version I

mm

0,25...0,45

Gasket thickness

mm

0,75...0,90

Version II

mm

0,45...0,70

Gasket thickness

mm

1,0...1,1

 Compressor (compressed air installation)

Number

Designation

Engine 372.9 , 374.9, 376.9, 386.9

BA13.30-B-1001-01A

Air compressor (MB) head and cylinder to engine block

M8

Nm

35

 Compressor (compressed air installation)

Number

Designation

Engine 372.9 , 374.9, 376.9, 386.9

BA13.30-B-1002-01A

Air compressor (MB) intake valve

M40x1.5

Nm

180

 Compressor (compressed air installation)

Number

Designation

Engine 372.9 , 374.9, 376.9, 386.9

BA13.30-B-1003-01A

Air compressor outlet valve (MB)

M6

Nm

10

 Compressor (compressed air installation)

Number

Designation

Engine 372.9 , 374.9, 376.9, 386.9

BA13.30-B-1004-01A

Pre-assembly of the air compressor (MB) outlet valve

Nm

20

 Compressor (compressed air installation)

Number

Designation

Engine 372.9 , 374.9, 376.9, 386.9

BA13.30-B-1005-01A

Connecting rod cap bolt (MB air compressor)

Nm

15

Repair materials

Number

Designation

Order number

BR00.45-Z-1009-01A

Sealant Loctite 574, 50 ml

A 001 989 89 20 10