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Vehicle Info NeededLine Pressure Booster Kit 45RFE, 545RFE, 65RFE, 68RFE
Ships on 09/15/2026
Lowest Price Guarantee- Line Pressure Booster Kit
- 45RFE, 545RFE, 65RFE, 68RFE
- For Use In Gas or Diesel Applications
- Includes Wiring Harness and Pressure Regulator Spring
Sonnax line pressure booster kit RFE-LB1 is an improved design over a simple resistor circuit. Featuring an integrated chip (IC) circuit and a stronger pressure regulator spring, this new kit delivers 10 psi increase at lower pressure range and 25 psi increase at higher pressure ranges. Only Sonnax line pressure booster kits provide progressive pressure increase which gives you smooth engagements and lower load on the pump at idle, but a greater increase in pressure as the transmission is worked harder.
Highlights - Allows for shorter shifts and increased torque capacity without creating low-speed harshness
- Progressive preasure increase as driving conditions become more demanding
- Improved clutch holding capacity for increased durability
- Greater sensor voltage range which reduces potential for error codes
- Fits both gas and diesel applications
- Includes integrated chip wiring harness and pressure regulator spring
Affordable Kit for Big Performance without a Big Price Tag
The larger boost valves and stronger PR springs in Sonnax booster kits raise line pressure the SMART way by controlling pressure increase progressively with the demand of driving conditions.
- Simple, affordable parts require no special tools or reaming to install.
- Slightly stronger springs provide a modest base line pressure increase. Unlike other, stronger aftermarket springs, Sonnax springs won't overload the pump at idle.
- Larger boost valves deliver demand-based line rise without low-speed harshness. How Progressive Boost Works:
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The combination of Sonnax booster kit valves and springs gives you the best of both worlds: a modest pressure increase at the low end, with a high-end pressure that is equal to or greater than that of other aftermarket kit springs.
The combination of boost valves and springs is the ONLY way to progressively increase line pressure.
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