Toyota Previa / Estima / Tarago
Brake Booster Solution – Third Generation (ACR50 / GSR50 / XR50)
Third-generation Toyota Previa platforms develop a brake booster issue as they age.
Internal vacuum leakage appears gradually, often after 10 years of use, leading to hard brake pedals on cold starts, inconsistent assist, and reduced braking confidence — especially on fully loaded vehicles.
The real challenge is not only the failure itself, but the fact that the original OEM brake booster has been discontinued and is no longer available from Toyota.
BCB addressed this problem by sourcing compatible brake boosters directly from Japan through original supplier channels.
Although the external layout remains similar, the internal structure is updated and the housing diameter is increased by half an inch, allowing improved assist capability and more stable response.
For right-hand drive vehicles, installation is a direct bolt-on using the original OEM master cylinder.
For left-hand drive vehicles, BCB supplies a matched master cylinder with correct port orientation and an upgraded bore size from 7/8" to 15/16", ensuring proper hydraulic balance.
Before shipment, every brake booster is recalibrated by BCB to suit passenger load, vehicle mass, and daily driving comfort — focusing on predictable control rather than aggressive braking.
This is not a cosmetic upgrade.
It is a practical, long-term solution for vehicles meant to continue carrying families safely and comfortably
