Install the car on a lift or inspection ditch and disconnect the wire from the terminal «minus» battery. Raise the car, remove the engine mudguard and drain the coolant from the radiator and cylinder block, for which the heater tap is opened and the drain plugs on the radiator and cylinder block are unscrewed (just two plugs).
Disconnect the exhaust pipe 3 mufflers (see fig. 20) from the exhaust manifold, unscrewing the nuts of its fastening and the bolts of fastening to the cylinder block of the bracket 1. Remove the bracket 2 (see fig. 35) inlet pipe of the coolant pump by unscrewing the nuts attaching to the pipe and exhaust manifold flange.
Lower the car, remove the air filter by disconnecting the crankcase ventilation hoses from the cylinder head cover and from the carburetor and disconnecting the warm air supply hose from the warm air intake. Close the carburetor with a technological plug.
Disconnect the wires from the spark plugs and the ignition distribution sensor, from the sensors for the oil pressure control lamp and the coolant temperature gauge, from the limit switch and the carburetor solenoid valve. Remove the ignition distribution sensor with the high voltage wire mounting bracket by disconnecting the vacuum hose from the carburetor and the distribution sensor.
Disconnect the fuel supply hose from the fuel pump, and the fuel drain hose from the carburetor. From the inlet pipeline, the vacuum extraction hoses to the econometer and the vacuum brake booster are disconnected. From outlet pipe 3 (see fig. 33) engine cooling jacket disconnect the hoses going to the radiator, thermostat and heater.
Disconnect the carburetor throttle and air damper cables from the engine. Remove the front toothed belt guard and cylinder head cover.
Set the gearshift lever to neutral position and turn the crankshaft clockwise so that the mark on the flywheel (see fig. 52), visible in the hatch of the clutch housing, was against the middle division of the scale. In this case, the mark on the camshaft pulley (see fig. 6) should be against the alignment mark on the back cover of the toothed belt.
Loosen the axle nut 7 (see fig. 25) tension roller 6 and remove the axle together with the roller and spacer ring 5. Then remove the belt from the camshaft pulley.
Holding the camshaft pulley from turning with fixture 67.7811.9509 or some lever with grippers for the pulley holes, unscrew the mounting bolt and remove the pulley 4 with the key.
Unscrew the nut securing the rear cover of the toothed belt to the cylinder head. Unscrew the mounting bolts and remove the cylinder head with gasket.
Install the cylinder head in the reverse order, following the recommendations set out in Sec. «Engine Assembly». The gasket between the head and the cylinder block cannot be reused, so replace it with a new one.
If the cylinder head bolts are loose (length exceeds 135.5 mm), I will replace them! new. Bolts are tightened in a certain sequence (pic. 18, a). To ensure a reliable seal and eliminate the tightening of the bolts during vehicle maintenance, the cylinder head bolts are tightened in four steps:
- 1st reception - with a moment of 2 kgf-m;
- 2nd reception - a moment of 7.1-8.7 kgf-m;
- 3rd reception - turn the bolts 90°;
- 4th reception - again tighten all the bolts by 90°.
Pic. 18. Order of an inhaling of bolts of fastening of a head of cylinders (A) and nuts of fastening of cases of bearings of a camshaft (b)
Nuts of fastening of a reception pipe of mufflers establish new. Old nuts must not be used.
After installing the cylinder head, check and adjust the clearance in the valve mechanism, the tension of the camshaft drive belt, the carburetor drive and the ignition timing.