04 2500 HD ABS problem

[vtdunn]

My truck had intermittent ABS activation at low speeds, cleaned speed sensors and problem not fixed. Replaced both speed sensors, and now the ABS activates every time, at about 5-8 MPH. Brought to dealer and told I need 2 new hubs, at about total cost of $1250. I didnt have it done, not knowing if this will definetly fix the problem, as they could not assure me it would!!

[MT-2500]

Originally Posted by vtdunn

My truck had intermittent ABS activation at low speeds, cleaned speed sensors and problem not fixed. Replaced both speed sensors, and now the ABS activates every time, at about 5-8 MPH. Brought to dealer and told I need 2 new hubs, at about total cost of $1250. I didnt have it done, not knowing if this will definetly fix the problem, as they could not assure me it would!!

You need to get ABS codes to see what the problem is.
Did the dealer give you the codes no.?

Are speed sensors replacable seperate or are the made in the hub bearing?

1250 is a little steep for hub bearings.
Go to your local parts place and price the good BCA or national bearaing for it.
The add 150 labor.
And post back total price.

[vtdunn]

The truck never threw any codes, my buddy hooked up his scanner. The speed sensors are brand new, they are seperate, and I put 2 new GM sensors, which made it worse. Inside the hub, looks fine, no rust, clean and the stars look fine. I can get aftermarket hubs for bout $200 a piece.

[MT-2500]

Originally Posted by vtdunn

The truck never threw any codes, my buddy hooked up his scanner. The speed sensors are brand new, they are seperate, and I put 2 new GM sensors, which made it worse. Inside the hub, looks fine, no rust, clean and the stars look fine. I can get aftermarket hubs for bout $200 a piece.

Are the 200$ aftermarkt hubs the good BCA or National or timpkin/ Or the cheap el cheap 0 90 day white box specials?
Do they come with speed sensors?
Are your tires all the same size and same air pressure?

You need to get it on A good ABS brake capable scanner
Watch all wheel speed sensor MPH readings and make sure they match and also make sure they match you truck MPH.

[j cAT]

Originally Posted by vtdunn

The truck never threw any codes, my buddy hooked up his scanner. The speed sensors are brand new, they are seperate, and I put 2 new GM sensors, which made it worse. Inside the hub, looks fine, no rust, clean and the stars look fine. I can get aftermarket hubs for bout $200 a piece.

I 've been there,,, done that several times.....just this past summer . I did another abs slow speed activation... the rust is not ON the sensor pick up....it is the sensor mounting hole face that the sensor seats on...this surface needs sanding and if necessary use a fine file...then paint with extend rust neutralizer or other product ....

after mounting the sensor measure the voltage ...the voltage must be with the wheel spinning by hand at a good rate 350MV a/c minimum....

if you did this properly you should get 580MV a/c...that what I get....

If you get 300mv a/c that is the problem...this is measured at the sensor connector...also I would use the originals,,,,not the sensors you just bought...or you can test and see if the new sensors are a problem or good..



lets say you get new hubs....these holes may require a shim pad...so this could get complicated if hubs need replacing...



this is also a recall so check if it still applies to your vehicle..

[j cAT]

It Only Takes .001 Of Rust To Cause This...

[vtdunn]

Yeah, chevy says no recall for my vehicle. But the other day while driving, I didnt notice a new vibration or growl at about 70 MPH, now that I think of it, could that be an indication of a bad hub?

[j cAT]

Originally Posted by vtdunn

Yeah, chevy says no recall for my vehicle. But the other day while driving, I didnt notice a new vibration or growl at about 70 MPH, now that I think of it, could that be an indication of a bad hub?

the noises could be many things...

On the sensors ....the voltage as I described WILL reveal to you that the sensors are or not puting out the correct voltage level..

this testing is required...

[kenny-1907]

I just recently had to have a hub / bearing assembly relpaced (the other one was done about 2 years ago) and I was having the same problem off and on the last couple of weeks where at low speeds the ABS was activating. I was told that when the bearings wear out and get loose it causes more distance between the sensor and the ring causing a reading out of the norm and causes the ABS to activate. After the hub / bearing was replaced, I no longer have the problem. I will also say that $1250 seems steep even for a 2500HD. I just had both upper ball joints, both front shocks, left front hub / bearing assembly, the right front inner tie rod end relpaced and an alignment done at a cost of $1430.

[Schrade]

Originally Posted by vtdunn

Yeah, chevy says no recall for my vehicle. But the other day while driving, I didnt notice a new vibration or growl at about 70 MPH, now that I think of it, could that be an indication of a bad hub?

Might or might not.

I would probably try to stick to the described inspection and testing.

5 - 8 mph at start-up is when ABS does a self-test. In some vehicles, it is pretty loud, like a low burp, or deer grunt... Yours is doing just as it should, if the test fails.

[vtdunn]

Well I bought 2 new timken hubs, slapped them on in about 3 hrs, and the problem is gone!! Guess the dealer was right, but for a fraction of the cost, everything is good for now, til the next issue arises, seeing the entire undercarriage is rusted real bad. Thanks to the inventor of that liquid road salt!!

[j cAT]

Originally Posted by vtdunn

Well I bought 2 new timken hubs, slapped them on in about 3 hrs, and the problem is gone!! Guess the dealer was right, but for a fraction of the cost, everything is good for now, til the next issue arises, seeing the entire undercarriage is rusted real bad. Thanks to the inventor of that liquid road salt!!

that is great you have solved all your problems...thanks for the feedback...


I hope you applied the rust inhibitor where the sensors mount....as the rust will cause the sensors to be forced out..eventually ...

did you ever measure the sensor voltage..?

[vtdunn]

To tell you the truth I never checked voltage, I just changed them out. I then applied Weatherpruf, made by Kano Labs, to the entire undercarriage, including the area around the ABS sensor. This was after I appled a rust inhibitor to the undercarriage also.

[j cAT]

Originally Posted by vtdunn

To tell you the truth I never checked voltage, I just changed them out. I then applied Weatherpruf, made by Kano Labs, to the entire undercarriage, including the area around the ABS sensor. This was after I appled a rust inhibitor to the undercarriage also.

well the voltage check is a good thing to do,,,, then in the future you will know exactly what your vehicle should have as the proper output to satisfy the computer abs....input..

with the rust protection in place this should keep down the problem in this area...usually in the fall I go over the vehicles and cover any rust issues...this really pays off if you keep longer than 7 years in our rust belt regions...

thanks for the reply ...