Fixing the ABS on the 80

[Von Hayek]

I posted this in the 80 section, but received no response, so I am hoping that someone in the club might have an answer.

Before I starting doing the drill down in the factory service manual, I am hoping that someone has a quick fix for me.

My '94 80 started to have the common problem of having the ABS activate when coming to slow stop. The light was not on.

Per the advice of many, I took each front sensor out and cleaned them off. The driver's side did have some metal filings on them.

After cleaning them, the ABS light has come on with codes 31 and 32 indicating malfunctioning senors at both front hubs. It is dangerous to drive, as at high speed braking the ABS will function incorrectly and make the truck lurch from one side to the other. I almost wrecked it on the first test drive I made.

Any thoughts?

 

[emorth]

31 = Right Front sensor fault
32 = Left Front sensor fault
Make sure there is no crud on the end of the sensor that "looks" at the teeth. Make sure the gap between the sensor and the teeth is correct. Make sure the teeth are clean and well formed with no cracks, chips or needed orthodontia. Check the contacts inside the connector where the sensor plugs into the wiring harness to make sure they are clean.

That's it for my 2 cents worth. If you want, we can look at the output of the sensors on an oscilloscope to see if the waveform is clean and well formed.

Ed

 

[Von Hayek]

Kind offer Ed. I think that the spacing would be the most likely problem. The reason I took them out was to clean them, so they really don't have any crud on them. And I didn't mess with the birfs, so I can't imagine that the teeth are fouled. I think that I will take them out again and make sure the mating surfaces are extremely clean. I will check the connector contacts as well. And then, on to your oscilloscope.

 

[Von Hayek]

Well, the problem turned out to be an error by the mechanic.

I was working over top of the knuckle when I reinstalled the sensors, and I did not realize that I had not seated the o-rings on the sensors. So each sensor was about 1/8" higher than they should have been.

I just seated them and the problem was fixed. I love problems that get solved with no expense of money.

 

[Stumpalama]

Nicely done sir! I'm glad it was a nice, cheap fix.

 

[StaleAle]

You need to fire that sorry, piece of **** excuse for a mechanic

 

[Von Hayek]

You need to fire that sorry, piece of **** excuse for a mechanic

I can't afford to.

 

[SAS]

Way to go, Bart.

 

[Von Hayek]

Way to go, Bart.

Tracy! Are we going to see you in the east this year?

 

[iptman]

Tracy! Are we going to see you in the east this year?

GSMTR registration is open!

 

[SAS]

Tracy! Are we going to see you in the east this year?

GSMTR registration is open!

There are a few guys here from Tornado Alley who are talking about going--but I probably won't be among them.

Y'all just remember that I'm at the 1/2-way mark for a Moab trip, and I have space to accommodate several!