OVER 250 SOLD! Ships for FREE today! Part: New Vacuum Power Brake Booster Fits: Toyota 4Runner | Land Cruiser | FZJ80 | FJ80 Years: 1993 • 1994 • 1995 • 1996 • 1997 Part Number: 4461060792What is it for?A brake booster is to braking what power steering is to steering. A brake booster uses a stored vacuum to overcome the high fluid pressure in a car's braking system. With a brake booster, the driver does not have to exert much force on the brake pedal when applying the brakes. A brake booster is also sometimes called a "vacuum brake booster" for this reason.How do I know it's time to replace it?The primary indicator of a faulty brake booster is a stiff brake pedal. Again, this is similar to the experience of power steering being out, which stiffens the wheel of the car. If it takes more force than usual to bring the vehicle to a stop, then very likely the brake booster is failing or has failed completely. This does not mean that the brakes themselves have failed.