05 screw stx 4x4 - 4.6l auto. 120k miles

Ok, thought my brakes pads were ready to be changed, due to fading in the pedal. The abs light would come on 25 to 35 miles into my 42 mile morning commute. So, without checking them I went to autozone and picked up new pads. I got home pulled the front wheels to find my year old pads were still new looking... hmmm, new, bigger problem...

So I figured Id check the brake fluid, it was fine and at the level mark. Then I figured it had to be either the master or booster is going bad.... but, I had to check the rears just to kill my curiosity. Pulled the right rear wheel and found a bad bad sign. It appears my axle seal has been leaking for a while. There was a tiny puddle on the rim... I checked the brake line, it seems fine.


So on to my question. Would the oil spray from the axle cause the brake fade in the pedal and would it also create the abs light after the miles stated above? I damn near hit a car in front of me in heavy traffic and your typical traffic brake check. I know the oil spraying all over the rotor will make it not stop.... but one out of 4, wouldnt it still have plenty of stopping power?


Another, I once knew, but have since forgotten, which set(front or back) does most of the stopping on a vehicle, or f150 for that matter. Im thinking rear, but its been a long time and Im second guessing myself.



If I go to autozone, will their scanner pull up the event causing my abs light to come on?

Thanks for the help.

Ken

 

Ok, I replaced the rear axle bearing and seal. However, I still need to chase down my abs/braking issue.

It has to do with the abs module or master/booster.

Question, does the computer give a code when the abs light has been activated? Would my local autozone be able to scan for the issue?

 

The front brakes on all cars does the most work because when braking the weight of the vehicle shifts forward. That's why the front rotors are usually larger.

As for your brakes fading, I think it's most likely the master cylinder because i wouldn't think the brake booster failing could cause as much a difference as you're describing. Also the abs unit failing shouldn't cause it either. Mine hasn't worked at all in 40K miles, and the only difference is that my wheels lock up easily on rainy days lol.

 

I'm pretty sure that the ABS system is a fail safe system. If the computer finds any fault it will disable ABS, but you will still have brakes, just without ABS so it will lock up on you. If the ABS light did come on, then there should be a DTC code stored in the computer. You can go to AutoZone and they can read it for you, post it once you got it and we would be able to help you out more. The ABS system is complicated and expensive to just start throwing parts at, with the DTC code you can narrow it down.

 

isn't there a problem with the, i think it's called, the actuator rod in the master cylinder? they sometimes break or bend and cause problems with braking. sometimes it just needs to be adjusted.

someone help me out here.

i don't believe brake fade would be caused by abs. isn't its main function to pulsate the pedal when wheel lock up is detected?