B. Bring piston to TDC on compression stroke in cylinder to be adjusted. Normally both tappets will be at their lowest point of travel.
C. Extend pushrod adjustment, collapsing lifter until piston assembly is in contact with HL2T spacer and pushrod is tight. If tappets contain oil, as when pushrods are readjusted after engine has been run, or if all oil was not removed during installation, extend pushrod adjustment until valve is open (about four additional turns of adjusting screw). Allow five minutes for hydraulic unit to bleed down. If pushrod can be turned with fingers after bleeding down, lifter is not completely collapsed, and this step must be repeated.
NOTE:Perform this operation on one cylinder at a time. Do not turn engine until pushrod adjustment is complete. 5
CAUTION: Turning engine while valve is held off the seat could result in valve-to-valve or valve-to-piston contact and serious valve train damage.
D. Loosen pushrod adjustment until pushrod can be rotated with the fingers with slight drag.
NOTE:Some engine builders prefer to adjust pushrods another one- half turn looser. This provides additional travel for the valve in the hydraulic piston assembly. Additional travel can improve the ability of the hydraulic unit to pump up and maintain zero valve lash.