Pontiac FIREBIRD 1972 Service Manual page 535

SIX CYLINDER ENGINE 6-23
not they are within specified limits. As with previous ser-
vice operations concerned with lifters, cleanliness is para-
mount. The tester cup and ram should be thoroughly
cleaned, and testing should be done in an area free of dust
and dirt. The testing procedure is described in the follow-
ing steps:
1. Fill tester cup to approximately one inch from top
with special fluid which is 'available from tester
manufacturer.
2. Swing weight arm up out of the way, raise ram, and
position lifter into boss in center of tester cup.
3. Adjust ram (with weight arm clear of ram) so that the
point is positioned on the set line (marked "S").
Tighten jam nut to maintain setting.
4. Operate lifter through full travel of plunger by pump-
ing weight arm to fill lifter with test fluid and force
out air. (Lifter must be completely submerged at all
times.) Continue pumping for several strokes after
definite resistance is detected.
5. Raise weight arm to allow plunger spring to expand
fully; lower arm onto ram and commence turning
crank slowly (1 revolution every 2 seconds).
Time indicator travel from lower line (first line above
set line) to line marked .094 or 3/32", while still
rotating cup with crank (Fig. 6-27). Lifter is satisfac-
tory if rate is between 12 and 65 seconds.
CYLINDER HEAD OR GASKET
Fig. 6-27 Testing Leak-Down Rate
Disconnect coil to distributor primary wire lead at
coil and remove coil.
8. Remove rocker arm cover. Back off rocker arm nuts,
pivot rocker arms to clear push rods and remove push
rods.
9. Remove the cylinder head bolts, cylinder head and
gasket. Place cylinder head on two blocks of wood to
prevent damage.
REMOVE
REPLACE
1. Drain cooling system and remove air cleaner.
2. Disconnect accelerator pedal rod at bell crank on
manifold and fuel and vacuum lines at carburetor.
3. Remove carburetor and heat shield.
4. Disconnect exhaust pipe at manifold flange, then
remove manifold bolts and clamps and remove mani-
folds and carburetor as an assembly.
5. Remove fuel and vacuum line retaining clip from
water outlet and disconnect wire harness from tem-
perature sending unit and coil, leaving harness clear
of clips on rocker arm cover.
6. Disconnect radiator hose at water outlet housing and
battery ground strap at cylinder head.
7. Disconnect spark plug wires and remove spark plugs.
1. Place a new cylinder head gasket in position over
dowel pins on cylinder block.
2. Carefully guide cylinder head into place over dowel
pins and gasket (Fig. 6-28).
3. Coat threads of cylinder head bolts with sealing com-
pound, and install finger tight.
4. Tighten the dylinder head gradually with a torque
wrench. Tighten bolts following sequence in Fig. 6-
29. The final torque should be 95 lb. ft.
5. Install valve push rods through openings in the cylin-
der head and seat them in lifter sockets.
6. Install rocker arms, balls and nuts and tighten rocker
arm nuts until all push rod play is taken up (Fig.
6-22).