ABS anti braking system 2?

[brods]

I know this is a rerun, but we can’t post to old threads and I do have a specific question about what is happening. We can save the debate about ABS’s usefulness (uselessness?) for a different thread, lol.

I rarely have the ABS go off and the few times it has I back off the brakes, reapply gently and modulate so the ABS doesn’t go off. So I am not real experienced in how the ABS actually feels and how it behaves when it is “working normally”. There have been two events that I hope those that know the ABS system can explain. I’ve read the FSM description of operation and still don’t understand what happened. 2005 2500 4x4

For some background, the truck eats right front wheel sensors. I’ll be on the fourth one once I replace the current bad one. In the meantime it gives the chime and dash lights, then they go away and come back again and again. Trouble code is for intermittent right front signal. In the past this hasn’t been an issue as the sensor typically totally fails and the lights stay on until a new sensor is installed. This time the intermittent part is ongoing and I was hoping to wait for warmer weather to replace it. Twice now the ABS kicked in seemingly as soon as the brakes were applied. Then oh sh#t, rather than just the right front having no braking, NONE of the brakes work! The pedal then has to be mashed which then causes major over braking.

I’m assuming at the time of the events the system had reset thinking all is well and then loses the right front signal during the braking event which causes it to think that the right front is locking up. So what gives? Why would the ABS prevent pressure buildup in the left front and rear circuit if it thinks the right front is locked up? Is this considered normal behavior (like if the right front was on ice and really locked up) and if so I’m seriously considering permanently disabling the ABS. Right now I’ve disconnected the sensor connector to make the ABS stay off until I can get a new sensor on.

 

[KParsons]

take the abs fuse out.

 

[Ozymandias]

Yes that is how ABS works, it levels down the brake force on all tires to keep the truck in the direction you drive.
For example if the right front has no traction and you apply the brake without ABS, your truck will do a sharp left corner because the left wheel has traction - the ABS prevents that.

To your problem, check the connection block at the ABS unit itself, i had more then once a bad connection at this point.
The trouble code for this is the same as the computer sees that bad connection as a faulty sensor.
Usually it isn't the sensor except there was a bad wheel bearing and the sensor was eaten up.

I had twice some cold soldering points in the unit itself, the design of it is more then worse, it could be Ford.
It is a self destruction unit by design, the more the ABS is used the faster it dies.
To me a half winter trip to Scandinavia was enough to destroy it (again) one time - and it was fixed just prior the trip.

 

[brods]

take the abs fuse out.

Doesn't that kill the speedo too?

Thanks Ozy. I know in theory ABS is a good thing, but I cannot say it has ever saved me from anything and I clearly remember the few times it has been counter productive.

 

[Ozymandias]

It saved my life once, for me that's fine.

But if it doesn't work as desired like in your case then it us a dangerous condition.

You did the right thing for the moment with disconnect that sensors circuit, done so it works like a standard brake system.
I wouldn't pull the fuse to.

 

[AEdelheit]

I put an ABS bypass switch in the cab on my truck so I can turn it off under certain conditions when it hinders more then helps, I totaled my last 06 because the ABS freaked out and I had no brakes. An 05 will be a little different but if you get a wiring diagram can still be easily done.

 

[Bob4x4]

If your truck is eating the same front sensor over and over again verify the hub bearing is good and that you’re not using Chinese sensors

 

[brods]

Wow. Right front sensor disconnected and both loose ends in plastic bags. Yesterday I go to stop and nothing! Heard the abs chatter and the dash ABS and brake lights are NOT on. The chime and lights came on and braking returned to normal. This is crazy, how could the system reset itself when there was no electrical connection at the right front wheel????? Is there anyway to permanently and positively deactivate the abs while keeping the speedometer?

 

[Ozymandias]

I think you really should see a dealer and do a proper diagnostic of that system.

You might suffer from the dreaded cold solder points in the unit itself.

There is a company in California that repairs the unit, like it was mentioned a couple days ago in another thread.