Volvo Penta MD5A Manuel d'utilisateur

Publ. No. 3061 Dec. 1975 WORKSHOP MANUAL MD5A Marine diesel engine ENGINE UNIT

21. Remove the steel wire which holds the filter. Remove and clean the wire gauze thoroughly. Afterwards remove the six screws which hold the cover

27. Fit new sealing rings. Note! The sealing rings must face the right way, see that they do not block the drain hole in the pump housing. Smear grea

29. Remove the cover’s centre screw, remove the filter 1 and clean it. 31. Depress the diaphragm and shake the pump arm spindle out until the pump

33. Clean the pump housing carefully and replace worn parts. Refit the manual pump arm. Press in the diaphragm and connect the pump arm to the diaph

Centrifugal governor 37. Clean the governor. Check to see if the weights 2 grip on their spindle or if there is too much movement between the spindl

41. Knock new screws in place and press a new bush in the connecting rod. Ensure that the lubricating hole 1 in the bush aligns with the hole in the

Replacing valve guides 45. The valve guides must be replaced if there is too much play between the valve stem and the valve guide. (See technical da

Valve and valve seat grinding 51. Machine the valve seats by milling or grinding them. Grind no more than is necessary to give the seat the correct

53. Check the wear on the rocker shaft. Also check that the tappet adjustment screw’s spherical part is neither deformed nor worn. The threads on th

Flywheel cover and hand starting mechanism 57. Unscrew nut 1 and remove it and washer 2 holding the hand starting gearwheel 3. Then remove the gearw

FOREWORD This workshop manual contains repair instructions for the MD5A marine diesel engine. The instructions concerning overhauling describe the mos

ASSEMBLING 61. Check that the liner is not scratched and that it is in good condition otherwise. Fit new 0-rings 1 in the block (2 off) and a new 0-

65. Remove any wear edges in the cylinder liner. Oil the cylinder liner and fit the piston in the block. Use a piston ring sleeve or tool 9992176.

69. Fit the gearwheel on the camshaft’s opposite end. 71. Fit a new gasket for the transmission cover. Afterwards fit the transmission cover. Fix t

73. Release the plunger 8 mm (0,3150 in.) and measure the distance from the transmission cover face to the adjusting screw’s contact point on the co

77. Fit a plane packing and then fit the sump. Note! On earlier engines a rubber seal was used. This is to be replaced by a plane packing. 79. Repl

81. Fit the fuel filter. Place sealing rings on both sides of the fuel pipe unions. 83. Connect the injector pipe, the temperature and oil pressure

85. Place the key for the gearbox connecting drive on the crankshaft on the gearbox side. Heat the connecting drive and fit it onto the crankshaft. L

INJECTION ANGLE CONTROL 89. A Wilbär tube is used when checking the injection angle. Fit the Wilbär tube on the pressure pipe nipple. 91. Open the

93. Fit the exhaust elbow and the gearbox. Use new gaskets. Check that the rubber damper is not damaged. BLEEDING THE FUEL SYSTEM 94. Fuel system

Wiring Diagram Cable Marking Designation Colour mm2 A.W.G. A White 6 9 B Black 1.5 15 B’ Black 0.6 19 B” Black 0.75 18 C Red 6 9 C’

CONTENTS Presentation 2 Dismantling Electrical system, thermostat housing cylinder head 3 Flywheel, fuel injector pump 4 Oil pump, tran

FAULT TRACING The fault finding chart given below only covers the most common faults which occur. Engine will not start Engine stops The engine does

Special tools for the MD5A Part No Designation 884538 Drift for pressing out valve guides 884549 Drift for pressing in valve guides

TECHNICAL DATA General Type designation Effect (DIN) at 40 r/s (2500 r.p.m.) No. of cylinders Bore

Connecting rod journals Diameter, standard mm (in.) Diameter, undersized, 0,250 mm (in.) Diameter, undersized

Lubrication oil filter Designation Lubrication oil pump Type Spring for pr

TIGHTENING TORQUES Cylinder head nuts* Cylinder head studs Screw for a gearbox drive on crankshaft Flywheel nut B

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Presentation 1. Connection for hand start 2. Fuse box 3. Thermostat housing 4. Decompression lever 5. Injector 6. Oil filler Cap, engi

Repair instructions Dismantling 1. Drain the cooling water and the oil from the engine. Clean externally afterwards. Loosen the water hose between th

5. Remove the flywheel nuts. Spanner jaw width 55 mm (2 5/32”). Use a wooden shaft or something similar as a counter force in the flywheel spokes. 7

9. Remove the pump screws. Position the ball in the centre and remove the pump. 11. Remove the governor by loosening the hexagonal set screw (1), th

13. Remove the lubricating oil pump. Discard the gasket. 15. Remove the gearwheel on the camshaft’s flywheel side (4 screws). Then remove the cams

19. Bearing replacement. Press out the camshaft bearings if they are damaged or if the wear is too great (see technical data). Clean the bearing hou