Volvo MD5A, Workshop Manual

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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 the screw and the locknut must be
undamaged.
Oval rocker arm bushes are to be replaced. Pressing in and
out is performed with drift 884560. Press the bush in so that
the oil hole assumes the position shown in the figure. The
bush is reamed to a light push fit after it has been pressed
in. Lubricate the shaft and assemble the rocker mechanism.
Pressure testing the nozzles
55.
Check the shape of the jets at an opening pressure of
185 kp/cm
2
(2631 p.s.i.). Also check that the fuel spray
discontinues simultaneously at all four holes and that no
subsequent drops appear.
Adjustment of opening pressure
56. The opening pressure is adjusted with adjustment
washer 1, which is available in thicknesses between 1 mm
(0.0394 in.l and 1,95 mm (0.0768 in.) with a difference of
0,05 (0,0020 in) mm between each size. Dismantle the
nozzle and replace the washer with a thinner or thicker
washer depending on whether the pressure is to be reduced
or increased. Assemble the nozzle and check the opening
pressure and jet shape. Continue until a satisfactory result is
obtained.
54.
Fit the rubber seal 1 on the inlet valve. Use tool 884497.
Oil the valve sterns before they are inserted in their
respective valve guides. Afterwards fit the valve springs,
collars and collets with the help of a valve compressor.
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