Volvo Penta TAMD61A, Руководство по ремонту

Страница: 44 / 88

42
Repair instructions
16
Install the spring and nut. Tighten the nut loosely.
Valve seat, replacement
Special tools: 9992479, 998976
17
Turn the tool clockwise, using even movements, and
without pressing. The cutters are fed automatically.
Turn the tool until the cutter bits stop cutting.
Remove the nut and lift off the cutting head.
1
The valve seat should be replaced when distance (A) ,
measured with a new valve, exceeds
TAMD61/62 TAMD63 TAMD71/72
Inlet .......... 1.5 mm 1.0 mm 3.0 mm
Exhaust .... 1.5 mm 1.0 mm 2.0 mm
2
The old valve seat should be removed by grinding two
notches in the seat, and then splitting it with a cold
chisel. As an alternative, an old valve can be tack
welded in several places, and the old seat can then be
driven out.
Grind down the head of the scrapped valve so it can
be pushed down below the edge of the seat.
Weld with a MIG/MAG welder, cover the area round
the weld to avoid getting weld spatter stuck anywhere.
WARNING! Be careful not to do any damage to
the cylinder head.
18
Clean the cylinder head carefully. Then check the
depth of the grooves by putting the cutting head back,
without the spring and nut, and turn it a few times un-
der
hand pressure. If the tool cuts, the grooves do not
have the correct depth.
This check must always be done since swarf can get
under the collar of the cutting head.
The burrs left by the edges of the grooves should be
left in place.
If these burrs are broken off, the edges could be dam-
aged, which would impair the sealing properties of the
grooves.
NOTE! The first time the grooving tool is used, after
the bits have been adjusted, the finished groove must
be checked with a dial gauge.
During this check, any burrs on the edge of the
grooves must be carefully removed, so that the dial
gauge holder seats correctly against the cylinder
head.