Skip the auto shop - Our mechanics make house calls

Q: Brake pedal goes to the floor when the engine is on

asked by on

My brother has a 2000 Blazer. When the car is on, the brake pedal has no brakes and they get down to the floor. But when the car is off, the pedal feels solid. I'm not sure if I should change all calipers or check for air.

A: The first thing you'd want to do of cou...

The first thing you'd want to do of course is pull off all the wheels and look for the leaks. But if you have no leaks, yours is the classic sign of a bad brake booster. When brake boosters go bad, you step on them with the engine off and will notice the pedal is nice and hard. When you start the engine, they go right to the floor. If this is what you are seeing, it's probably a brake booster. But check for leaks first because brake boosters are pretty expensive and are no fun putting on. If you want to have to have this looked at first, a technician from YourMechanic can come to your home of office to inspect your brakes and replace your brake booster if necessary.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Engine bogging down when making a turn

For your 2002 Oldsmobile Bravada, you may have a problem in the transfer case causing the AWD to be engaged when it shouldn't. In this case, the transfer case encoder is not working correctly and should be replaced. The problem...

Q: Oil leak 1997 Chevy Blazer 4WD

Hi there. The oil leak could be, nothing more than, a loose oil filter. Another possibility, a leaking oil filter adapter gasket. Oil likes to travel down (via gravity) and should be properly diagnosed as there are several possible places...

Q: Brake pedal is to small for my big foot friend. Is there another larger (longer or wider) to put on?

Hello, thank you for writing in. There are pedal extensions on the market you can purchase to raise the pedal up higher. Typically there are other ways to adjust the pedals as well (typically for performance or handicap purposes). These...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.