Today I had FOT replace wheel bearing seal on the driver side drive axle . On the way home, I noticed the "ABS Brake" alert was illuminated. I stopped and looked for anything unusual. The rotors were warmer than I expected, but I don't know what is normal. Rotors on each side on the drive axle were about the same temperature. Front rotors were cooler, but about the same on both sides. (Be sure to check rotors with a thermometer rather than a finger -- D'oh! :o )
When I restarted, the "ABS Brake" illuminated until I had rolled a short distance. After moving a bit, the lamp went out, but then came back on after a few miles. I repeated the "shut down/start up" drill several times on the way BACK to FOT. Each time, the "ABS Brake" lamp would light when I turned on the key, and then go out after the coach started moving. That is the normal sequence of operation. However, the lamp would illuminate again after driving 0.5 to 10 miles. The behavior was consistent. The system would not reset on "stop/neutral/roll." The system would reset on "key off/start/roll." I repeated the drill several times.
I expect a sensor may have moved during the "seal job" and is now signalling a fault, but not immediately.
Has anyone knowledge or experience to share regarding the issue? I prefer to find a solution other than simply disabling the alert lamp. I'll see what FOT folk have to offer tomorrow.
That is my thought. David
The first place to look is the last place touched. Advice I was given 35 yrs. ago. I still find it useful.
Probably a speed sensor got pushed back when the rotor was re-installed. Anytime a rotor is installed the speed sensor should be pushed in against the rotor. Too much clearance will cause intermittent signals. The sensors should be pushed in all the way against the rotor, they will self adjust from rotation of the rotor.
J.D.,
I can verify the veracity of your advice. On a trip one time, the front disk brakes on my Town and Country started making a noise. After I stopped, I touched the disk to see if there was a groove.
Will never do that again; wish I hadn't the first time!
Trent
Wayne snugged up the ABS sensor on the "corner" on which he worked. That did not solve the "ABS Brake" alert issue. He told me that he encounters about one failure a year of an ABS sensor that is related to a brake job or seal job. The ABS sensors accumulate a bit of wear each time they are set in association with working on the brakes. The wear will eventually lead to failure. He reported that the brake system on that corner would have to be taken apart -- again -- to replace the sensor.
I chose to leave the system in its broken state. The brakes will work fine, but will not have the ABS functionality. I only recall one instance of ABS action in about 65K miles of driving our coach. There was some ice on a turnout. The ABS did not make much difference in the event except for dramatically dropping the air pressure in a brief moment.
I'll do a more research to find out more about how the system is constructed. I've even had some thoughts of getting some heavy tools and having a go at myself, but I don't think I'm mean enough -- and careful enough -- to do the job properly.
I offer thanks to those who shared information.
If it's like the system in our '03, only that wheel will not have ABS function when the light is on; the others should still work. You should check your manual.