![background image](http://html1.mh-extra.com/html/yuchai/yc4d60-d21/yc4d60-d21_maintenance-manual_3664228022.webp)
22
the tightening nut. A correct valve clearance should be able to allow the feeler gauge
move with slight resistance.
Fuel injection pressure adjustment
Technique demand
Fuel injection pressure 23±0.5MPa
26±O.5MPa(turbo charge)
Fuel injection pressure adjustment: Remove the pressure-adjusting screw thimble, screw
in or out the pressure-adjusting screw as required. Screwing in means the increase of the
injection pressure, on the contrary, screwing out means the decrease of the injection
pressure. The fuel injection pressure can be adjusted on special test rig.
Oil pressure adjustment
Figure 11 Oil pressure adjustments
Technical data :
Oil pressure at idle speed ≥ 0.1MPa
Oil pressure at rated speed : 0.25
~
0.6MPa
Oil pressure adjustment: The oil pressure
can be adjusted by the adjusting screw of relief
valve on the oil filter. During adjustment, remove
the nut on the relief valve, unscrew the locking
nut, screw in the adjusting screw with
screwdriver, then the oil pressure will be
increased. If the adjusting screw is screwed out, the oil pressure will decrease. After the
adjustment, fasten the locking nut and nut. If the adjusted oil pressure does not meet the
requirement, check the trouble in the oil passages carefully and troubleshoot them.