ABS Light

[Jim Dick]

My ABS light had been on for a couple of years. Tried several times to have repair shops look at it but they couldn't get into the system. Finally had a Spartan rep take a look and he found both front sensors were shorted to ground. The actual problem was the "brain".

One can easily go without ABS but it really helps in wet conditions. I did have it fixed even though I never experienced a problem with braking without it.

 

[BayareaBill]

  Jim
  My Class C is a 97  on a 96 E 350  Chassie as well,and I definitely have sensors  at the rear drums.I will try and talk to the repair shop that fixed mine and get a better idea of what to look for or expect to see.Please bare with me and I promise I wont say it again,but I still suspect a front sensor malfunction.
                                                            Bill

 

[BayareaBill]

  Jim
  Talked to the shop that repaired mine,I gave you some misinformation earlier,the rear sensors  are on both sides of the rear differental,a wire does go to them,they are approx  a 1 inch square black box.very simple to un plug and replace,confirmed 35 a piece,but dont replace them unless you see visable damage,as I dont want to steer you towards a repair that doesnt fix the issue.Hope this is helpful .          Bill

 

[Conquest aka Robert]

Bayareabill;

Thanks for the info it helps when you know where to look. I was looking at the brake drum area never thought to look inboard by the pumpkin.

 

[bingo_57]

OK due to saver weather (snow with rain) wasn't able to get under neath it. OK call me a sissy! But I will as soon as this white crap moves on.... Beginning to wonder if it ever will, but that's a different subject. The unit has drum brakes on the rear & disk on the front, for sure on the sincere on the front. Will double ck on the rear. Just didn't see anything looking like that with another line (wire) going to it Again my thanks to everybody.

Jim
:-\

 

[bingo_57]

OK just got from underneath that big thing in the drive way, there IS a line going to the front of the diff on top of it. All connections are tight. I don't understand how it operates the brakes.... Is there a electrical line running inside the diff going to the brakes?? But like I said the only line going to the receptive wheels is the brake fluid line.

Jim
AKA: Bingo

 

[swinn]

The electrical line does not operate the brakes.  The sensor detects the speed of the wheels and/or shafts and the ABS computer uses that information to control the brakes when necessary with a hydraulic actuator that is controlled by the ABS computer.  The actuator pushes fluid in the hydraulic line to operate the brakes.

 

[bingo_57]

OK that makes since to me.. So the only sincere I really can do anything with are the ones on the front wheels. They are visible and exposed the elements. I cked the wire & connectors at each wheel, all seemed good.

Jim
AKA: Bingo

 

[swinn]

On some vehicles the ABS light can be diagnosed through the OBD II port on the vehicle with a proper reader.  On your 97 ford chassis I believe you'll need something that supports Ford Enhanced Data View.  The inexpensive OBD code readers won't do it.  Specialized readers can get expensive and it is probably more cost effective to go have the codes read at a shop and find out why the light is on according to the computer.  Some auto repair stores may be able to read the code for you for free.  It would be easier once you know why the ABS system is complaining.

 

[bingo_57]

Thanks Swinn. This helps loads! I'll get back to everyone here.

Jim
AKA: Bingo

 

[Clay L]

There is a good explanation of how ABS systems work HERE . The system does not apply the brakes instead but decreases it so the tires won't lock up.

 

[bingo_57]

Clay that's a grate site thanks! I think I'll do some CKing of grounds & unplug & repluge some lines this weekend and see if that makes any difference. We live 47 miles from town so just "running" it over is not really an option.

Thanks
Jim
AKA:Bingo

 

[bingo_57]

OK all, Cked every thing and all looked & felt tight unplugged and replug ed front sincere. Going to take it out this coming weekend to see whats up. Let you all know what comes out!


Jim
AKA: Bingo

 

[Clay L]

The electrical line does not operate the brakes.  The sensor detects the speed of the wheels and/or shafts and the ABS computer uses that information to control the brakes when necessary with a hydraulic actuator that is controlled by the ABS computer.  The actuator pushes fluid in the hydraulic line to operate the brakes.

As far as I know the ABS system does not actuate the brakes but rather relieves the brake pressure by bypassing some of the brake pressure.
The older systems I am familiar with could only decrease the pressure a relatively small amount. That way if the ABS system failed in the low pressure mode you would still  have the ability to stop the vehicle.