F-150 brakes solid when engine off, but go to the floor when on.

Asked by 84dna Jul 21, 2020 at 03:50 PM about the 2014 Ford F-150 FX4 SuperCrew 4WD

Question type: Maintenance & Repair

2014 Ford F-150. Part of master cylinder recall. Have replaced the master
cylinder 2X. Checked the Power booster, not an issue. Checked the ABS
modulator, it is fine. When I push the brake with engine off, very solid. I'm not
losing brake fluid. When I turn the engine on, the pedal sinks to the floor, and I
have no brakes. What do I check?

1 Answer
315

jnebeker75 answered 4 years ago

what you are describing points to a bad power booster. The way we check power boosters is by pumping up the brakes with the key off till the pedal gets stiff, with your foot still holding the brake pedal start the car. the brake pedal should drop a little bit. if its going all the way to the floor the your power booster is losing vacuum.

3 people found this helpful.
Mark helpful

Your Answer:

Related Questions

Shortcuts

Search Ford F-150 Questions

CarGurus Experts

  • #1
    OJ
    Reputation
    42,600
  • #2
    Gene Arnett
    Reputation
    16,040
  • #3
    Rowefast
    Reputation
    15,890
View All

Find great deals from top-rated dealers

Search

Related Models For Sale

Used Chevrolet Silverado 1500
195 Great Deals out of 5,877 listings starting at $2,975
Used GMC Sierra 1500
128 Great Deals out of 6,516 listings starting at $3,975
Used RAM 1500
451 Great Deals out of 15,772 listings starting at $4,950
Used Ford F-250 Super Duty
18 Great Deals out of 1,178 listings starting at $8,995
Used Toyota Tundra
31 Great Deals out of 1,361 listings starting at $6,255
Used Toyota Tacoma
46 Great Deals out of 1,074 listings starting at $9,995
Used Ford Mustang
58 Great Deals out of 1,366 listings starting at $4,995
Used Chevrolet Silverado 2500HD
27 Great Deals out of 1,241 listings starting at $9,500
Used RAM 2500
49 Great Deals out of 2,148 listings starting at $13,650
Used GMC Sierra 2500HD
21 Great Deals out of 1,519 listings starting at $5,500
Used Ford Explorer
75 Great Deals out of 2,091 listings starting at $3,995

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.