Brake concern

[crazyduetoiowa]

I have a 2005 4.2 with 89k 4wd. The brake pedal occasionally goes farther towards the floor when coming to the end of a stop. I have bled the brake lines. All brake pads, rotors, and lines are good. Could it still be air in the lines?


Derek

[Tech II]

The only way that air can get into the system, is if there is a leak....

Is the fluid level dropping in the reservoir?

What is the thickness of the pads? Condition of the rotors?

[crazyduetoiowa]

Brake fluid level is steady. The pads are over 50%. Rotors are in good condition. It does this issue randomly. It's when you are at the end of a stop.

[DeltaP]

Sticking caliper/s?

[rhandwor]

Originally Posted by crazyduetoiowa

I have a 2005 4.2 with 89k 4wd. The brake pedal occasionally goes farther towards the floor when coming to the end of a stop. I have bled the brake lines. All brake pads, rotors, and lines are good. Could it still be air in the lines?


Derek

Sometimes when a master cylinder is going this happens. If you pump the brakes does the brake petal return to normal?

[DeltaP]

Loose, worn caliper too. I agree on the m/cyl.

[Schurkey]

First thing that comes to my mind when the pedal sinks at the very end of a stop...

...is the ABS controller. The ABS will be taken out-of-circuit at the end of a stop; perhaps under 3--4--5 mph. At that point, it no longer prevents brake pressure from going to the wheel cylinders.

But, hey, I've been wrong before.

[gmtech1]

Is it possible that you are having ABS activation at the end of the stop? This will give you a feeling of pedal fade, but you should also here the ABS activate.

[Schurkey]

Originally Posted by gmtech1

Is it possible that you are having ABS activation at the end of the stop? This will give you a feeling of pedal fade, but you should also here the ABS activate.

Other way around. ABS active during the higher-speed part of the stop, but goes inactive under a certain MPH, so the fluid is allowed to transfer to the wheel cylinders...and the pedal drops a little.

[crazyduetoiowa]

The brake calipers are not sticking. I lubed the slides. I checked all four. So what should I do to check out the possibility of the ABS issue. The ABS light is not on. My family has owned it for the last 6-7 years so I know it isn't some crappy dealer trick/cover up. Thanks!

[maxwedge]

An abs sensor could be bad and no lite as it just fools the abs into thinking one wheel is locked just as you come down under say 10 mph, a full scan and live road test scan with an abs scanner will look at sensor inputs when the condition occurs.

[crazyduetoiowa]

Okay I bought one sensor and replaced it on the one I thought was bad (front pass). This did not fix it so I put the old one one the drivers side. Still no change. I will inspect the rear ABS sensors soon. If I pull the fuse will it cause the system light to stay on even after I replace the fuse? Just to double check that it's the ABS?

Thanks!

[maxwedge]

You are going to waste time and money doing it this way, again an abs scan will pinpoint a skewed sensor.

[rhandwor]

Originally Posted by crazyduetoiowa

Okay I bought one sensor and replaced it on the one I thought was bad (front pass). This did not fix it so I put the old one one the drivers side. Still no change. I will inspect the rear ABS sensors soon. If I pull the fuse will it cause the system light to stay on even after I replace the fuse? Just to double check that it's the ABS?

Thanks!

Google OTC-3874 2014 domestic and abs
This will fix you up quickly.
Autel maxi check pro
Autel ebs-301
The Autel is cheaper but helps pin point problems.