Brake pedal to the floor

IRWINT

MEMBER
2000 FORD F-150
5.4L
V8
4WD
AUTOMATIC
2,001,228 MILES

With no "brake warning light", pedal sinks to floor almost immediately. Pumping helps but sinks to floor each time. Five seconds Ford dealer changed badly needed brakes both front and rear. Computer assisted brake bleed. No avail. Changed my master cylinder. No avail. Now with vehicle off, brakes bleed down to floor then two pumps gets it hard until you turn power on. Start. What is next? No external fluid leaks found. Is there any checks for the ABS control module? Or the Power Boost canister on firewall? Can these new problems? Please help!

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
47,513 POSTS

Hello,

The first thing I would do is gently use three vise grips on put them on the brake flex hoses. Then push the brake pedal down if the pedal stays good then we know the problem is at the wheels, if it fads then we know its either the master or ABS unit.

Here is a guide that can help as well

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

Please let us know what happens, we are interested to see what it is.

Cheers, Ken