• Erratic line pressure
  • High governor pressure
  • 2nd Gear starts
  • Delayed engagement
  • Harsh Reverse
  • Pressure over 230
  • No TV control
  • Overheated converter
  • Blued converter


Bore wear at the pressure regulator valve on high-mileage vehicles allows orificed balance line pressure to leak to the sump and affects converter feed and line pressure control.


Sonnax drop-in pressure regulator valve kit incorporates a PTFE seal and end plug with O-ring to prevent balance oil pressure leakage.

TH200, TH200C

Pressure Regulator Valve Kit
Part No. 65912-01K

View Instructions Find a Distributor

High-mileage vehicles with GM TH200 or TH200C transmissions often experience poor line pressure control due to a worn pressure regulator bore. This can result in high cooler pressure as well as converter and/or friction element failure. The hardened steel valve continuously oscillates within the cast-iron pump bore, resulting in wear. Orificed line/balance pressure is then allowed to leak past the valve and exhaust to the sump. This prevents the pressure regulator valve from staying in its normal regulating position. Sonnax pressure regulator valve kit 65912-01K that eliminates these problems.

  • Sonnax pressure regulator valve has been modified to incorporate a PTFE seal ring that properly separates the orifice line from the pump suction, preventing cross leakage
  • O-Ringed end plug ensures proper back pressure to the pressure regulator valve
  • Kit eliminates the need to replace the pump casting to ensure pressure control
  • Drop-in Zip Valve™ parts install quickly and easily
Learn More About Zip Valve™ Drop-In Repairs
  • Valve
  • Seal Ring PTFE
  • O-Ring
  • End Plug
  • Retaining Ring
  • TH200, TH200C Pressure Regulator Valve Kit 65912-01K
  • TH200, TH200C Pressure Regulator Valve Kit 65912-01K