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Category: Ford
Satisfied Customers: 26083
Experience:  ASE CERTIFIED TECHNICIAN ADVANCED LEVEL SPECIALIST. Wisconsin certified emissions state inspector
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2006 f-150 5.4 brakes go to floor when engine starts and

Customer Question

2006 f-150 5.4 brakes go to floor when engine starts and will not pump up. Replaced master cylinder and bled with power bleeder.
JA: Have you checked the battery, particularly the terminal connections? Are they corroded?
Customer: not corroded. brakes pump up ok when engine off
JA: Are you fixing your F150 yourself? What have you tried so far?
Customer: I began by up grading front calipers to power stop components after this the problem began. I then replaced master cylinder with new
JA: Anything else you want the mechanic to know before I connect you?
Customer: no
Submitted: 8 months ago.
Category: Ford
Expert:  AMEDEE replied 8 months ago.

Hello and welcome!

My name isCustomerand I can assist you with your question.

Expert:  AMEDEE replied 8 months ago.

Are you looking for possible causes or would you like some suggestions?

Customer: replied 8 months ago.
Customer: replied 8 months ago.
looking for the cause and how to fix
Expert:  AMEDEE replied 8 months ago.

Ok, no problem.

Does the brake pedal improve if you were to clamp off all 4 brake hoses?

Customer: replied 8 months ago.
have not tried that but the brakes firm up with engine off
Expert:  AMEDEE replied 8 months ago.

Clamping off all brake hoses going to each caliper will help you pinpoint the root cause. I bet the brake pedal will be rock solid once you do this.

I have a feeling it will be the front calipers that were just installed.

Customer: replied 8 months ago.
they were direct replacement but tomorrow I will put the old ones back on and try
Expert:  AMEDEE replied 8 months ago.

Just clamp off the hoses and see if there is an improvement. This should take less than 10 minutes.

Customer: replied 8 months ago.
Expert:  AMEDEE replied 8 months ago.

I am glad I can help!

It has been a pleasure working with you. Please dont forget to honor your good faith deposit by rating my answer as "5 STAR SERVICE" for assisting you today.

Keep in mind, we can still continue this conversation at no further cost to you even after you rate my answer. Just reply back to me using this page and I will get it and get back to you ASAP!

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Please let me know if you have any further questions.

Expert:  AMEDEE replied 8 months ago.

YES, you are more than welcome to check these things and reply back tomorrow.

I just ask that you dont forget about me.

Expert:  AMEDEE replied 8 months ago.

Hello! It'sCustomerfrom just answer.

I am just checking in to see if you had a chance to run the test and came up with any results?

Let me know!