Symptoms:

  • Low line pressure
  • No converter apply
  • Hydraulic-related converter codes
  • Burnt clutches
  • Soft shifts
  • Poor shift quality

Cause:

Wear in the signal accumulator piston bores of the control solenoid valve body casting allows valuable VFS Signal pressure loss. This pressure is used to help control shift feel, regulate line fluid pressure and control pressure of the converter clutch control valve.

Correction:

Restore hydraulic control by installing the drop-in Sonnax signal accumulator piston kit to quickly and easily restore hydraulic integrity.

8L45, 8L90

Signal Accumulator Piston Kit
Part No. 154740-06K

Includes 4 piston sets which fit any of 7 locations.

You need this if... View Instructions Find a Distributor

GM 8L45 and 8L90 transmissions often suffer burnt clutches, shift concerns, low line pressure and/or converter apply complaints due to excess wear in the signal accumulator piston bores in the control solenoid valve body casting. This wear allows valuable VFS signal pressure to exhaust, preventing proper shift control, line pressure regulation, and/or converter clutch apply.

The Sonnax drop-in signal accumulator piston kit 154740-06K allows bores to be reconditioned quickly and easily with no reaming required. The hydraulic integrity of the VFS signal pressure circuits are re-established, and future wear prevented with positive sealing and wear resistant components.

  • Hardcoat anodized aluminum piston combats premature wear
  • Annular grooves to reduce wear rate
  • Highly wear-resistant sleeve to prevent future wear
  • Positive sealing O-ringed plug prevents leakage in already worn bores
  • Mating spring to re-establish OE dampening action
  • Drop-in Zip Valve™ parts install quickly and easily
Learn More About Zip Valve™ Drop-In Repairs
  • Sleeves (4)
  • Pistons (4)
  • Springs (4)
  • O-Rings (6) 2 Extra
  • End Plugs (4)

  • 8L45, 8L90 Signal Accumulator Piston Kit 154740-06K
  • 8L45, 8L90 Signal Accumulator Piston Kit 154740-06K

You need this if...

8L45, 8L90 Signal Accumulator Piston Kit Vacuum Test Locations