The LPC signal damper used in listed Ford and GM transmissions dampens any fluid pressure spikes in the LP signal (EPC) circuit from reaching the main pressure regulator valve. This prevents any significant and unintended pressure variations from affecting the main pressure throughout the circuit, and helps to provide smooth operation of the valve.

When the bore or piston wears, effective dampening of LPC signal pressure is not maintained and can leak to exhaust. This can result in harsh shifts and excessive line pressure.

Sonnax LPC signal damper piston kit 105740-04K allows long-lasting and quick repair of the lower valve body casting without reaming. The O-ring provides a positive seal against critical pressure loss even in worn bores.

• Hardcoat anodized aluminum piston combats premature wear
• Annular groove added to the piston reduces wear rate
• Highly wear-resistant sleeve to prevent future wear
• O-Ring provides positive seal to prevent critical pressure leakage in already worn bores
• Mating spring re-establishes OE dampening action
• Drop-in Zip Valve™ parts install quickly and easily