Power brake booster
Thread Starter
Racer
Joined: Oct 2007
Posts: 284
Likes: 6
From: Palm PA
Power brake booster
Can anyone let me know if this is normal for power brakes? With the engine off and no vacuum present, pressing as hard on the brake pedal as I can the pedal goes 1/2 way to the floor and is solid as a rock. Start the engine and the pedal is almost on the floor (too close for me) and feels spongy but still stops the car. Is the brake booster bad or does something have to be adjusted?
68 Vetteman
68 Vetteman
Pro
Joined: Jul 2010
Posts: 691
Likes: 25
From: Boynton Beach Florida
Sounds more like a master cylinder going bad. Power booster when bad would have a hard pedal (both feet on the pedal, am I gonna stop kinda hard) when the engine is running. Spongy pedal going to or near the floor is classic master cylinder or possible need for bleeding the entire brake system due to air in the lines.
Since master cylinders are inexpensive, easy to install and usually the root of most common brake problems I would replace it and bleed all the calipers starting with the right rear, left rear, right front then left front noting that each caliper has 2 bleed screws (one on each half of the caliper, inner and outer) and you should have a great pedal when done.
Good Luck
Since master cylinders are inexpensive, easy to install and usually the root of most common brake problems I would replace it and bleed all the calipers starting with the right rear, left rear, right front then left front noting that each caliper has 2 bleed screws (one on each half of the caliper, inner and outer) and you should have a great pedal when done.
Good Luck
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
Can anyone let me know if this is normal for power brakes? With the engine off and no vacuum present, pressing as hard on the brake pedal as I can the pedal goes 1/2 way to the floor and is solid as a rock. Start the engine and the pedal is almost on the floor (too close for me) and feels spongy but still stops the car. Is the brake booster bad or does something have to be adjusted?
68 Vetteman
68 Vetteman
Check hydraulic system, not booster.
