HYDRAULIC LASH ADJUSTER (HLA) CONSTRUCTION/OPERATION [F2]
id011094122200
Construction
• The HLA in the rocker arm automatically maintains the valve clearance at 0 mm {0 in} at all times. The result is that tappet noise is eliminated and there is no need for adjustment of valve clearance.
• The HLA is composed of the body, plunger and check valve. Oil is supplied through the rocker arm. The body has an O-ring at the outer circumference to act as an oil seal. If there is a malfunction in the HLA, it must be replaced as a unit.
Operation
• When opening the valve, hydraulic pressure within the body prevents the plunger from moving.
• When the valve closes, the plunger is forced downward by the spring, thus automatically adjusting the valve clearance to 0 mm {0 in}.