4L80E. The OE pressure regulator valve design prevents adequate cooler flow at low RPM and high pressure / demand conditions, which can create overheat complaints. Additionally, in 1999-later vehicles, the factory EPC pressure was set high at idle, resulting in engine surge conditions. The Sonnax Line-to-Lube pressure regulator valve provides a significant increase in cooler flow under low RPM and high pressure conditions that benefits all vehicles with high EPC pressure at idle.
Replacement pressure regulator valve has an encapsulated check valve that allows regulator flow to the converter charge / lube circuit at vehicle idle.
- Check valve prevents converter or pump drain-back.
- Improves converter release pressure.
- Prevents engine surge at idle in 1999-later vehicles.