Nissan Sentra/Pulsar/NX 1982-1996 Repair Guide

Valve Springs

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REMOVAL & INSTALLATION



Removal or installation of the valve springs requires use a valve spring compressor. There are several designs, like the leverage type, jawed type or C-clamp type. The C-clamp type is the most common for cylinder head service where the heads have been removed. All of the other types that are used with the cylinder heads installed require the use of compressed air to keep the valves from falling down inside the cylinder. A GM type Air Adapter tool No. J-23590 or equivalent can be used to retain the valves in the cylinder head using compressed air.

The valve springs are removed and installed as part of the valve procedure found earlier in this section. If only a spring replacement is required, refer to the valve stem seal procedure with the cylinder head installed. The same air pressure method may be used to retain the valve while only a spring is replaced.

INSPECTION



See Figures 1 and 2



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Fig. Fig. 1: Measuring the spring height and squareness. Make sure the closed coils face downward



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Fig. Fig. 2: Testing spring pressure

  1. Place the valve spring on a flat, clean surface, next to a square.
  2.  
  3. Measure the height of the spring and rotate it against the edge of the square to measure the distortion (out-of-roundness). If the spring height among springs varies or the distortion exceeds more than 0.06 in. (1.6mm), replace the spring(s). The valve spring squareness should not exceed: 2.20mm (outer) or 1.90mm (inner).
  4.  
  5. A valve spring tester is needed to test the spring pressure. Compare the tested pressure with the pressures listed in the Valve Specifications chart in this section.
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