Hyundai Coupes/Sedans 1986-1993 Repair Guide

Jet Valves

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Jet valves are used on 1986-89 Excels and Sonatas with 4-cylinder engines.

REMOVAL & INSTALLATION



See Figures 1 through 5

  1. Remove the rocker arm assemblies.
  2.  



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Fig. Fig. 1: Removing or installing the jet valves



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Fig. Fig. 2: Jet valve used on 1986-89 1468cc engines



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Fig. Fig. 3: Disassembling the jet valve

  1. Using special socket tool MD998310 (09222-21300), remove the jet valve. Care must be taken not to twist the socket while removing the valve, it can be easily broken.
  2.  



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Fig. Fig. 4: Installing a new jet valve seal



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Fig. Fig. 5: Cross section of an installed jet valve

  1. The valve may be disassembled using special tool MD998309 (90222-21400). Using the tool, compress the spring and remove the valve retainer lock. Remove the spring retainer and spring. Don't separate the jet valve from the valve body or leakage and improper operation will result. Using pliers, pull off the valve stem seal and discard them.
  2.  
  3. Make sure that the valve slides smoothly in the valve body. If any roughness or sticking is noted or any other damage is found, replace the valve and valve body as a unit.
  4.  
  5. Check the valve head and seat for wear, damage and binding. The valve stem diameter should be 4.30 mm. The angle of the valve face and seat is 45 . The jet valve spring free length should be 29.600mm for both Excel and Sonata and its load at length should be 5 1 / 2 lbs. @ 21.5mm for Excel and 7.7 lbs. @ 21.5mm for Sonata.
  6.  
  7. Using special jet valve seal installer MD998308 (09222-21400) drive the new seal onto the valve body. If this tool is not used, the seal could become deformed and oil will leak into the combustion chamber.
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  9. Using MD998309 (09222-21500), compress the valve spring and reinstall the retainer locks.
  10.  
  11. Apply a coat of clean engine oil to a new O-ring and install it in the groove in the jet valve body.
  12.  
  13. Apply a coat of clean engine oil to the threaded portion of the valve body and seating surface and thread the assembly into place in the head using finger pressure only.
  14.  
  15. When the valve body is seated in the head, tighten it, with tool MD998310 (09222-21300), to 13-16 ft. lbs. Be very careful to keep the tool perfectly straight on the valve body to prevent distortion or damage to the valve assembly.
  16.  

 
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