Symptoms:

  • Engine surge at idle
  • Low cooler flow

Cause:

Low converter release pressure at idle.

Correction:

This Sonnax kit allows the rebuilder to restore correct clearances for proper hydraulic control.

4L80-E, 4L85-E

Oversized Line-to-Lube Pressure Regulator & Boost Valve Kit
Part No. 34200-36K

Fits '99-later units.


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

GM 4L80-E and 4L85-E pressure regulator valve design prevents adequate cooler flow at low RPM and high pressure/demand conditions, which can cause overheat complaints. In ‘99-later vehicles, the factory EPC pressure was set high at idle, resulting in engine surge conditions. Sonnax oversized line-to-lube pressure regulator and boost valve kit 34200-36K provides a significant increase in cooler flow under low RPM and high pressure conditions.

  • Oversized pressure regulator valve has an encapsulated check valve that allows regulated flow to the converter charge/lube circuit at vehicle idle
  • Check valve prevents converter or pump drainback
  • Improves converter release pressure
  • End Plug
  • Pressure Regulator Valve
  • Pressure Regulator Spring
  • Boost Valve
  • Boost Sleeve

Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.

GM 4L80-E, 4L85-E, 400 Valve Body Layout

GM 4L80-E, 4L85-E, 400 Valve Body Layout

  • 4L80-E, 4L85-E Oversized Line-to-Lube  Pressure Regulator  & Boost Valve Kit 34200-36K
  • 4L80-E, 4L85-E Oversized Line-to-Lube  Pressure Regulator  & Boost Valve Kit 34200-36K

You need this if...

Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.

4L80-E, 4L85-E Oversized Line-to-Lube  Pressure Regulator  & Boost Valve Kit Vacuum Test Locations