Hydraulic Valve Lifter Assembly
NOTE:
Before replacing hydraulic lifter for noisy operation, be sure noise is not caused by improper collapsed lifter gap, worn rocker arms, push rods or valve tips. If lifter assembly is stuck in bore, use Hydraulic Lifter Puller (T70L-6500-A) or magnet.
- Hydraulic lifter assemblies must be installed in original locations. Remove cylinder head and related parts. Using lifter remover or magnet, remove lifters. Clean and inspect but do not mix components or positions. Parts are select-fitted and are not interchangeable.
- If lifter is sticking, disassemble and clean dirt, metal chips or varnish from components. If lifter check valve is not functional, obstructions may be preventing it from closing when cam lobe is moving lifter, or check valve spring may be broken. Clean or replace components as necessary.
- If plunger is not free in body of lifter, replace entire assembly. Plunger should drop to bottom of body by its own weight when assembled dry. Assemble lifter and check free operation by pressing down on cap.NOTE: If lifter has been disassembled and cleaned, be sure to fill with test fluid before installing in engine. New lifters already contain test fluid. When performing leak-down test, note that lifters cannot be checked with engine oil in them, only test fluid can be used.
- Place lifter upright in Hydraulic Lifter Leak-Down Tester (6500-E), and check leak-down rate. Leak-down rate is 10-15 seconds measure at .0625" (1.59 mm) plunger travel, under 50 lb. (22 kg) load.
- Inspect lifter base-to-cam lobe contact area. Surface must have smooth and convex contact face. Replace any lifter with flat or concave surface. Inspect related cam lobe for proper lobe lift. Replace camshaft (and lifters if necessary) if any lobe is worn beyond specification.
- Check lifter-to-bore clearance. Standard clearance is .0007-.0027" (.018-.069 mm). Service limit is .0050" (.130 mm) maximum. Standard diameter of lifter is .8740-.8745" (22.200-22.212 mm).