Volvo MD5A, Workshop Manual

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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 connecting rod. Ream or diamond
drill the bush to an accurate free fit. Check that the gudgeon
pin slides through the bush due to its own weight. (See also
the technical data.) Fit one of the circlips and oil the gudgeon
pin and connecting rod bush. Heat the piston to
approximately 70
0
C (158
0
F) and assemble the piston and
the connecting rod according to the marking. Note! The
gudgeon pin must be able to be pressed in easily. Fit the
other circlip.
43. Fit the piston rings with the help of piston ring pliers.
Start with the oil scraper ring in the lowest groove. The oil
scraper ring can be fitted either way. Continue with the
compression ring which is marked “TOP” on one side. This
marking shall face upwards when fitted. The piston ring with
the chromium insert is fitted last and can be fitted either way.
Cylinder head
44.
Remove the collets, the collars and the valve springs
with the help of a valve spring compressor. Remove the
valves. Remove the valve seal from the inlet valve. Burnt
valves are discarded if worn too much and damaged seats
are to ne machined when necessary. (See technical data.)
The valves and valve seats are to be ground together so that
the mating surfaces provide a complete seal.
42.
Control the dimensions of the piston with a micrometer.
Measure at right angles to the gudgeon pin holes at the
piston’s lower edge. Afterwards check the new rings’ play in
the piston ring grooves. (See technical data.)
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