Mazda Trucks 1994-1998 Repair Guide

Valve Lifters

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This procedure applies to hydraulic lash adjusters as well as valve lifters (tappets).

BLEEDING



The manufacturer does not recommend that the Hydraulic Lash Adjusters (HLA) be bled. Removing an HLA from its rocker arm will release its oil. If the HLAs are removed from the rocker arms, new ones should be installed using new O-rings.

  1. Before installing new HLAs, fill the rocker arm oil reservoir with fresh engine oil.
  2.  
  3. Apply fresh engine oil to the new HLA and its O-ring.
  4.  
  5. Install the new HLA into the rocker arm, taking care not to damage or distort its O-ring.
  6.  

REMOVAL AND INSTALLATION



2.3L and 2.5L Engines

See Figure 1

A special tool is required to compress the valve spring.

  1. Remove the valve cover and associated parts as required.
  2.  
  3. Rotate the camshaft so that the base circle of the cam is against the cam follower you intend to remove.
  4.  

If removing more than one cam follower, label them so they can be returned to their original position.

  1. Using special tool 49-UN01-135 or equivalent, depress the valve spring, as necessary, and slide the cam follower over the Hydraulic Lash Adjuster (HLA) and out from under the camshaft.
  2.  
  3. Remove each HLA.
  4.  
  5. Install the HLA and cam follower in the reverse order of removal. Lubricate the followers with SAE 50W engine oil meeting current API specification prior to installing.
  6.  

2.6L and 3.0L (MPV) Engines

See Figures 1 and 2

  1. Disconnect the negative battery cable.
  2.  
  3. Remove the valve cover.
  4.  
  5. Remove the rocker arm/shaft assembly.
  6.  
  7. If necessary, disassemble the rocker arm/shaft assembly, noting the position of each component to ease reassembly.
  8.  
  9. Check the surface of the Hydraulic Lash Adjuster (HLA) for wear and damage. If the HLA is worn or damaged, it must be replaced.
  10.  



Click image to see an enlarged view

Fig. Fig. 1: Remove the HLA from the rocker arm

  1. Remove the HLA from the rocker arm. Don't remove the HLA unless necessary, because oil leakage will occur if the O-ring is damaged.
  2.  

To install:


Click image to see an enlarged view

Fig. Fig. 2: HLA and oil reservoir

  1. Follow these steps to install the HLA:
    1. Pour clean engine oil into the oil reservoir in the rocker arm.
    2.  
    3. Coat the HLA with clean engine oil.
    4.  
    5. Place the rocker arm and HLA into a tub filled with clean oil, and then insert the HLA into the rocker arm, taking care not to distort the O-ring.
    6.  

  2.  
  3. Install the rocker arm/shaft assembly.
  4.  
  5. Install the valve cover.
  6.  
  7. Connect the negative battery cable, start the engine and check for leaks and proper operation.
  8.  

3.0L (B Series Pick-up) and 4.0L Engines
  1. Remove the upper and lower intake manifolds.
  2.  
  3. Remove the valve covers.
  4.  
  5. Remove the rocker arm/shaft assembly.
  6.  
  7. Remove and mark the pushrods for installation.
  8.  
  9. Remove the tappets with a magnet. If they are to be re-used, identify them.
  10.  

If the tappets are stuck in their bores, you'll need a claw-type removal tool.

  1. Coat the new tappets with clean engine oil and insert them in their bores.
  2.  
  3. Coat the pushrods with heavy engine oil and insert them into the bores from which they came.
  4.  
  5. Install the rocker arm/shaft assembly.
  6.  
  7. Install the valve covers.
  8.  
  9. Install the upper and lower manifold.
  10.  

 
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