Performed by; automobile mechanic,

Performed by; automobile mechanic, electrician, greaser and driver.
Operations and Specifications
Preventive maintenance No.2 includes all the operations performed during Preventive maintenance No.l and the following additional operations;
Engine
1. Disassemble the fuel filter-settler (Pig. 10.) and the fine fuel filter (Fig.21) and wash the filtering elements with gasoline.
When disassembling the filters, take care not to damage the gasket sealing the cover-to-bowl Joint,
2. On the 3HJI-131 truck, wash the air valves cm the fuel tanks and, using compressed air, blow through the valve pipes and tank interconnecting pipe 13 (Fig.22).
3. Remove, clean and wash valve 1 (Fig.23) of the engine crankcase ventilation system.
4. Tighten the bolts and nuts fastening the cylinder block heads of the engine and the intake and exhaust mani¬folds (Fig.9).
5. Listen to the operation of the valves and adjust, if needed, the clearances between the ends of the valve stems and the rocker surfaces which should be within 0.25 to 0.3 mm for the exhaust and intake valves (see Process Chart No.8).
Every other PM No*2 check the engine cylinders for compression (see Process Chart No.9).
6* Tighten the nuts of bolts 2 (Fig.24) of the engine front (9) and rear (16) engine suspensions and torque am. The nuts of bolts 9 of the rear engine suspension should be tightened to a torque from 20 to 25 kgf*m, and the nuts of bolts 2 and 16 of the front and rear suspensions,respectively, to a torque of 8 to 10 kgf*m.
7. Check the rivetted joints of the frame for condi¬tion by tapping with a hammer and see that the girder and cross-member flanges have no cracks. Loose rivets should be
replaced with bolts.
In addition to the above-mentioned operations, every 55*000 to 50,000-km run the following operations should be performed during PM No. 2.
8. Remove the cylinder block heads and remove the car¬bon deposit from the pistons and the combustion chambers. If needed, lap in the valves. Check to see that the engine in¬take manifold, ducts of the intake valves and the crankcase ventilation tubes are free from deposits.
. 9* In case of excessive oil consumption and smoking ex¬
haust, check the condition of the piston rings and replace, if needed. In the same operation, check the condition of the connecting rod bearings and replace, if needed* Tighten the bolts of the main bearing caps.
The tightening torque should be from 7 to 8 kgf«m for the connecting rod bearings and from 12 to 15 kgf m for the main bearings.