Sonnax Pressure Regulator Valve Kit for 6L45, 6L50, 6L80, 6L90

The Sonnax 104520-15K pressure regulator valve kit is designed to resolve common hydraulic issues in GM 6L45, 6L50, 6L80, and 6L90 transmissions. Excessive wear in the pressure regulator bore—particularly around the balance and outboard spools—can lead to fluid leaks, resulting in erratic line pressure, harsh or soft shifts, clutch failure, and transmission overheating. This drop-in solution restores pressure stability and ensures proper flow to the converter and cooler circuits.

The upgraded valve features hardcoat anodized aluminum for durability, extended spool lengths to bypass worn areas, and annular grooves that center the valve to prevent future side-load wear. The kit also includes a new outer spring that slightly increases line pressure by approximately 5 psi to improve performance across the operating range.

Note: Pump must be removed to install this kit. This is a direct replacement for the discontinued Sonnax kit 104520-14K. Includes:

• Pressure Regulator Valve
• Pressure Regulator Spring
• Checkball

Key Features:

• Hardcoat anodized aluminum construction resists premature wear
• Extended spool design operates in less-worn bore areas
• Grooved spools minimize side-load and bore damage
• Replacement spring improves pressure response (+5 psi)
• No machining or drilling required
• Easy drop-in installation

Common Symptoms:

• Erratic, high, or low line pressure
• Harsh or soft shifts
• Clutch slippage or failure
• Inadequate or no cooler flow
• Transmission overheating
• Torque converter performance issues

Cause:
Continuous oscillation of the OE regulator valve leads to wear in the valve bore, which disrupts hydraulic balance and reduces flow to critical areas.

Correction:
Install the Sonnax pressure regulator valve kit to reestablish precise pressure control and restore full transmission function.

Vehicle

BMW
1-SERIES 2006-2013 6 SP RWD L4 1.6L 2.0L L6 3.0L
X1, Z4, X1, Z4 2009-2016 6 SP R/4WD L4 2.0L L6 3.0L
1-SERIES 2006-2013 6 SP RWD L4 1.6L 2.0L L6 3.0L
5-SERIES 2006-2010 6 SP R/4WD L6 2.5L 3.0L
6-SERIES 2007-2013 6 SP RWD L6 3.0L
Z4 ROADSTER 2009-2011 6 SP R/4WD L6 3.0L
BUICK
PARK AVENUE 2010-2013 6 SP R/4WD L4 2.0L V6 2.8L 3.0L 3.6L
CADILLAC
CTS COUPE, CTS SPORT WAGON, CTS COUPE, CTS COUPE 2010-2014 6 SP RWD V8 6.2L
CTS 2007-2014 6 SP R/4WD V8 6.0L
ESCALADE 2007-2016 6 SP R/4WD V8 6.2L
ESCALADE ESV 2008-2016 6 SP R/4WD V8 6.2L
STS 2005-2011 6 SP RWD V8 4.4L
XLR/XLR-V 2005-2009 6 SP RWD V8 4.4L 4.6L
ATS 2012-2016 6 SP R/4WD L4 2.0L 2.5L V6 3.0L 3.6L
CTS 2008-2014 6 SP RWD V6 2.8L 3.6L
CTS 2013-2016 6 SP R/4WD L4 2.0L
CTS SPORT WAGON 2009-2014 6 SP R/4WD V6 3.0L 3.6L
SRX, XLR 2006-2009 6 SP R/4WD V8 4.6L
STS 2006-2013 6 SP R/4WD L4 2.0L V6 3.0L 3.6L V8 4.6L
ATS 2012-2016 6 SP R/4WD L4 2.0L 2.5L V6 3.0L 3.6L
CTS 2013-2016 6 SP R/4WD L4 2.0L
CTS SPORT WAGON 2009-2014 6 SP R/4WD V6 3.0L 3.6L
STS 2006-2013 6 SP R/4WD L4 2.0L V6 3.0L 3.6L V8 4.6L
CHEVROLET
CAMARO 2011-2015 6 SP RWD V8 6.2L
EXPRESS 2009-2016 6 SP RWD V8 6.0L 6.6L
SILVERADO 2013-2016 6 SP R/4WD V8 6.2L
SILVERADO HD, CORVETTE 2007-2016 6 SP R/4WD V8 6.0L
SUBURBAN 2500 2006-2013 6 SP R/4WD V8 6.0L
VAN FULL SIZE 3500 2010-2011 6 SP R/4WD V8 4.8L 6.0L 6.6L DIESEL
AVALANCHE 2008-2013 6 SP R/4WD V8 5.3L 6.0L
C-1500 2013-2015 6 SP 4WD V8 5.3L
CAMARO 2009-2015 6 SP RWD V8 6.2L
EXPRESS 2009-2016 6 SP R/4WD V6 4.3L V8 4.8L 5.3L
SILVERADO, SUBURBAN, TAHOE 2008-2016 6 SP R/4WD V6 4.3L V8 5.3L
VAN FULL SIZE 2500 2009-2011 6 SP RWD V8 4.8L 5.3L
CAMARO 2009-2015 6 SP RWD V6 3.6L
CANYON, T-SERIES 2014-2016 6 SP R/4WD L4 2.5L 2.8L V6 3.6L
COLORADO 2011-2016 6 SP R/4WD L4 2.5L 2.8L V6 3.6L
S-10, TRAILBLAZER 2012-2016 6 SP R/4WD L4 2.8L
GMC
SAVANA, SIERRA 2009-2016 6 SP RWD V8 6.0L 6.6L
SIERRA 2013-2016 6 SP R/4WD V8 6.2L
SIERRA HD 2007-2016 6 SP R/4WD V8 6.0L
SAVANA 2009-2016 6 SP R/4WD V8 4.8L 5.3L
SIERRA DENALI 2008 6 SP R/4WD V8 6.2L
YUKON 2006-2016 6 SP R/4WD V8 5.3L 6.0L 6.2L
YUKON XL 2008-2016 6 SP R/4WD V8 5.3L 6.2L
HOLDEN
CAPRICE 2012-2016 6 SP RWD V6 3.6L V8 6.0L
COMMODORE 2006-2016 6 SP RWD V6 3.0L 3.6L V8 6.0L 6.2L
SS PERFORMANCE 2013-2016 6 SP RWD V8 6.0L
CAPRICE, COMMODORE, COMMODORE 2012-2013 6 SP RWD V6 3.6L
SS PERFORMANCE 2013-2016 6 SP RWD V6 3.6L
PONTIAC
G8 2007-2010 6 SP RWD V8 6.0L 6.2L
G8 2008-2010 6 SP RWD V6 3.6L
TATA
ARIA 2015-2016 6 SP R/4WD L4 2.2L

Alternate Words: transmission and specialty driveline components, 104520-14K