Hydraulic Lash Adjuster Valve Lifters - Lifter Operation

GENERAL INFORMATION.

Oil is supplied to the lifter through a side hole in the lifter body, which

connects to the groove and hole in the plunger. The oil then passes through

the lifter metering valve and through the lifter push rod channel to the valve rocker arm.

While the lifter is moved by the camshaft cam,

the check ball valve seats on its seat and traps oil in the cavity under

the plunger. The lifter body and plunger then move as one unit. The plunger sleeve, moving the push rod, opens the valve. Under the action of

the valve spring resistance, a small amount of oil leaks from the plunger cavity through the radial clearances.

Because of this, the plunger also moves slightly relative to the lifter body. While the valve closes, the lifter moves down. When the valve seats, the plunger spring quickly returns it to

its initial position. The check ball valve then opens and passes oil into the plunger cavity. This removes the clearances in the valve train.