How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Dan Your Own Question
Dan, ASE Certified Technician
Category: Hyundai
Satisfied Customers: 1686
Experience:  Auto Technician
Type Your Hyundai Question Here...
Dan is online now
A new question is answered every 9 seconds

I start the car and the brake pedal goes to the floor, What

Customer Question

I start the car and the brake pedal goes to the floor
JA: Have you tried cleaning and oiling the brake pedal's pivot under the dash?
Customer: What would that have to do with the pedal sinking to the floor when the car is started
JA: What is the model/year of your Hyundai?
Customer: 2006 Hyundai Sonata
JA: Are you fixing your Sonata yourself? What have you tried so far?
Customer: Yes i am fixing it... I found a line seaping a very little bit and o repaired the line... I bled the whole sytem and nothing changed, it still goes to the floor when the car is started... With the car not running it has a brake pedal and as soon as the car is started, it sinks to the floor
JA: Anything else you want the mechanic to know before I connect you?
Customer: No
Submitted: 11 months ago.
Category: Hyundai
Expert:  Dan replied 11 months ago.

Hello my name is***** am an ASE Master Technician and I am glad to help you out with your question.

Expert:  Dan replied 11 months ago.

You may have a problem with the master cylinder. Otherwise, did you use a scan tool to bleed the abs? Sometimes air can get trapped here and you need a scan tool to get the brakes bled.

Customer: replied 11 months ago.
I was thinking that it was the vacuum assist but there is any change in the sound of the motor when the brake is applied which would indicate a vacuum leak and would point to the vacuum assist
Expert:  Dan replied 11 months ago.

The master cylinder is separate from the brake booster.

Customer: replied 11 months ago.
Do you think it would be the vacuum booster
Expert:  Dan replied 11 months ago.

Probably not.

Expert:  Dan replied 11 months ago.

A booster problem would cause a hard pedal probably not a soft one, soft indicates air in the lines.

Expert:  Dan replied 11 months ago.

Sometimes the seal in the master cylinder will leak, the fluid will enter the vacuum booster drum, pull the vacuum hose off the booster, insert a zip tie into the hole in the booster, use zip tie like a dipstick and see if any brake fluid is in there indicating a leak.

Customer: replied 11 months ago.
i have a hard pedal when the car is not running, with my foot on a hard pedal, car not running and i start the car, the pedal goes right to the floor
Customer: replied 11 months ago.
I have the master cyl off the car and i will check for a fluid leak and get right back to you
Customer: replied 11 months ago.
I took a 12 inch zip tie and slid it down the vacuum tube after removing the rubber hose and turned and twisted it around and retried this several times and found absolutely no sign of brake fluid
Expert:  Dan replied 11 months ago.

That's good that there is no fluid in the booster.

Expert:  Dan replied 10 months ago.

Hello again Dan here,

I am contacting you because the post has not been closed or rated.

This question is coming up on 7 days which means it will time out and close.

You have already paid to get this question answered, but you have not rated.

Let me help some more. Is there anything else I can help you with?

If I did not give you 5 star service, please let me know what I missed.

I do not get compensated for my time and resources unless you rate me.