Section 03-01A: Engine, 4.9L SFI | 1996 F-150, F-250, F-350 (4x2), F-150, F-250 (4x4) Workshop Manual |
| Description | Tool Number |
|---|---|
| Tappet Bleed Down Wrench | T70P-6513-A |
Service push rods (6565) are available in the standard length or plus or minus 1.52mm (0.060 inch) as a means for compensating for dimensional changes in the valve mechanism. Refer to the Ford Master Parts List for the appropriate color code.
Valve stem-to-valve rocker arm clearance should be within specifications with the valve tappet (6500). Refer to Specifications. Repeated valve reconditioning operations (valve and/or valve seat refacing) will decrease the clearance to the point that if it is not compensated for, the hydraulic valve tappet will collapse and cease to function, and could prevent the valve seat face from properly seating on the valve seat. Valve will be held open.
The positive stop rocker arm bolt eliminates the necessity of adjusting the valve clearance. However, to obtain the specified valve clearance, it is important that all valve components be in a serviceable condition and installed and tightened to specifications. Refer to Specificationsin this section.
To determine whether a shorter or a longer push rod is necessary, make the following check.
Install an auxiliary starter switch. Crank the engine (6007) with the key in the OFF position.
Make two chalk marks on the crankshaft pulley (6312). Space the marks approximately 120 degrees apart so that, with the timing mark, the crankshaft pulley is divided into three equal parts (120 degrees is one-third of the distance around the damper circumference).
Tighten the rocker arm bolts of the No. 1 intake and exhaust valves to specifications with No. 1 piston on TDC at the end of the compression stroke.
Slowly supply pressure to bleed down the valve tappet until the plunger is completely bottomed using Tappet Bleed Down Wrench T70P-6513-A.
Hold the valve tappets in this position and check the available clearance between the rocker arms (6564) and the valve stem tip with a feeler gauge.
Repeat this procedure for the remaining set of valves, turning the crankshaft (6303) with an auxiliary starter switch, one-third turn at a time, in the direction of rotation. At the same time, adjust the valves in the firing order sequence, 1-5-3-6-2-4.