Symptoms:

  • Low line rise
  • Poor shift timing

Cause:

The regulator boost valve wears the inside diameter of the boost sleeve.

Correction:

This Sonnax drop-in replacement pressure regulator boost sleeve is tightly toleranced to restore proper line rise control.

RE4F02A, RL4F02A

Pressure Regulator Boost Sleeve
Part No. 93990

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Vehicles with a RL4F02A transmission often have problems with poor shift timing and poor line rise. This can be caused by the reciprocating pressure regulator boost valve wearing the inside diameter of the boost sleeve. As this wear increases, pilot/boost pressure, which enters the sleeve, leaks past the valve and exhausts, resulting in poor line rise. The Sonnax replacement pressure regulator boost sleeve 93990 eliminates the above problems.

  • Sleeve has been manufactured from high-quality aluminum designed to resist wear
  • Sleeve has been closely toleranced to obtain the original minimal clearance with the boost valve
  • Drop-in Zip Valve™ parts install quickly and easily
Learn More About Zip Valve™ Drop-In Repairs

Will also work in some RE4F02A units. Compare sleeve I.D., depth, overall length, OD and feed hole location.

  • RE4F02A, RL4F02A Pressure Regulator Boost Sleeve 93990
  • RE4F02A, RL4F02A Pressure Regulator Boost Sleeve 93990