Section 03-01B: Engine, 5.0L HO and 5.0L Cobra
1993 Mustang Workshop Manual
IN VEHICLE SERVICE

Hydraulic Tappet

Before replacing a hydraulic tappet for noisy operation, ensure the noise is not caused by improper valve to rocker arm clearance or by worn rocker arms or push rods.

 

Removal

  1. Remove the intake manifolds and related parts.
  1. Remove the valve rocker arm covers. Loosen the valve rocker arm fulcrum bolts and rotate the rocker arms to the side.
  1. Remove the valve push rods and identify them so that they can be installed in their original positions.
  1. Remove the tappet guide retainer bolts.
  1. Remove the retainer and tappet guide plates. Identify the guide plates so they may be installed in their original positions.
  1. Using a magnet, remove the tappets and place them in a rack so that they can be installed in their original bores.

    If the tappets cannot be removed from their bores due to excessive varnish, etc., it may be necessary to use a claw-type tool or a magnet to remove them. Rotate the tappet back and forth to loosen it from the gum or varnish that may have formed on the tappet.

    If necessary to disassemble a tappet refer to Tappet Disassembly and Assembly as outlined.



 

Installation

Tappets and bores are to be lubricated with Engine Assembly Lubricant D9AZ-19579-D (ESR-M99C80-A) or equivalent before installation.

  1. Clean outside of tappets and install in the bores from which they were removed. If a new tappet is being installed, check the new tappet for a free fit in the bore in which it is to be installed. Lubricate the tappet and bore with Engine Assembly Lubricant D9AZ-19579-D (ESR-M99C80-A) or equivalent before inserting it in the bore.
  1. Install tappet guide plates in their original positions, then install guide plate retainer.
  1. Install the push rods in their original position. Apply Multi-Purpose Grease D0AZ-19584-AA (ESR-M1C159-A and ESB-M1C93-A) or equivalent to the valve stem tips and the push rod ends.
  1. Lubricate the rocker arms and fulcrum seats or roller arm assemblies with Engine Assembly Lubricant D9AZ-19579-D (ESR-M99C80-A) or equivalent. Position the rocker arms over the push rods and tighten fulcrum bolts to 24-34 Nm (18-25 lb-ft). Perform a valve clearance adjustment. Refer to Section 03-00.
  1. Install the valve rocker arm covers with a new service gasket or equivalent where specified.
  1. Install the intake manifold and related parts.
  1. Run the engine and check for leaks.


Mustang





Item Part Number Description
1A — Tappet Guide Retainer Plate Bolt (2 Req'd)
2 6C515 Roller Tappet Guide Retainer Plate
3 6585 Valve Push Rod (16 Req'd)
4 6K572 Guide Plate (8 Req'd)
5 6500 Roller Tappet (16 Req'd)
6 6A588 Fulcrum Guide (8 Req'd)
7 6564 Rocker Arm (16 Req'd)
8 6A528 Fulcrum (16 Req'd)
9B 390385 Fulcrum Bolt (16 Req'd)
A Tighten to 8-12 Nm (71-106 Lb-In)
B Tighten to 24-34 Nm (18-25 Lb-Ft)


Cobra





Item Part Number Description
1A — Tappet Guide Retainer Plate Bolt (2 Req'd)
2 6C515 Roller Tappet Guide Retainer Plate
3 6585 Valve Push Rod
4 6K512 Guide Plate (8 Req'd)
5 6500 Roller Tappet (16 Req'd)
6 6A585 Pedestal Assy (8 Req'd)
7 6C526 Roller Rocker Arm Assy (16 Req'd)
8B 391423 Rocker Arm Bolt (16 Req'd)
A Tighten to 8-12 Nm (71-106 Lb-In)
B Tighten to 23-34 Nm (18-25 Lb-Ft)