ABS KEEPS IN GAUGING

[Cadillac Bob]

Hey y’all my brakes when I slow to about 5 mph then to a stop are in gauging the abs. They also sometimes in gauge when just driving in a parking lot I haven’t checked out anything yet. but I did have a leak awhile back and thought it had leaked onto passenger side rotor/ brake. but now I’m thinking may be more to it? the shop I had fixing leaks said brakes were fine so I figured it was fluid and just driving and washing would go away as to cook or wash off fluids any thoughts on what it could be I plan to look later this week or if too busy the weekend.
Any advice is helpful.

thank you all

 

[SUBURBAN5]

Could be module. If I had this issue I get somebody to check for codes

 

[Chevy-SS]

99% of the time this is an ABS wheel speed sensor. Often times a code will give you a clue as to which wheel. The sensors are cheap, and easy to replace. Or the reluctor might be just dirty/rusty.

The green arrow on the pic points to where all the magic happens. The sensor picks up the little tabs on the reluctor ring. It's a tight tolerance, and once it gets dirt/rusty, the sensor can no longer function properly, thus you get the awkward low-speed activations.

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[spitanddirt]

A cracked reluctor ring or mismatched tire sizes can cause erratic signals to be sent to the module thereby engaging the ABS when it shouldn't. The brake switch "arms" the ABS unit for possible ABS engagement every time the brake pedal is pressed.

On pre-'95 you should be able to read flash codes from the ABS. '96 and later will require an ABS specific scan tool or a scan tool with ABS functionality like the Tech II or Snap-On equivalent.

What about parts swaps? Different transmission or axle ratios? Is the ABS module original to the vehicle or did it come from a junk yard?

You gave limited info about the vehicle, so I have to make a few assumptions.

Sent from my SM-N975U using Tapatalk

 

[Pinger]

A cracked reluctor ring or mismatched tire sizes can cause erratic signals to be sent to the module thereby engaging the ABS when it shouldn't.

Even tyre pressures out of whack can cause it.
Tyre mismatches can be borderline then ABS is triggered by driving over things like speed humps as one wheel speeds up over it then another.

 

[Cadillac Bob]

Thank you all for your help!!! As far as codes no lights are on. Which is why I made posting I’ve replaced one of the sensors like above a few years back yes was pretty simple to do. I did pull my fuse panel off inside drivers door and pull brake fuse it has some patina/corrosion on it going to it scratch off and then take next steps towards it being something else. Once again you guys are awesome for all of the information!!!

 

[Cadillac Bob]

Yes truck is basically 21 year old stock lol 2000 Escalade yes hmt400 edition very last of gmt400s tires are new around 1000 miles or less on them here’s a pic of her about month and a half ago she’s no junkyard Survivor lol

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[Cadillac Bob]

So I scraped off build up on fuse. And it’s better but just before I come to a complete stop the slightest abs in gauging so I’m thinking the speed sensors being changed will hopefully solve the problem. Now I just have to buy them and put them in lol!

 

[Chevy-SS]

Yes truck is basically 21 year old stock lol 2000 Escalade yes hmt400 edition very last of gmt400s tires are new around 1000 miles or less on them here’s a pic of her about month and a half ago she’s no junkyard Survivor lol

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Beautiful truck!!!! You keep her in nice shape, that's for sure... Well done....

 

[Nad_Yvalhosert]

The word is spelled "engage"

GM has multiple TSB's on Unwanted ABS Activation at slow speed. @Chevy-SS has the best illustration I've seen.
Rust builds up under the sensor, opening the air gap between the sensor and the tone wheel.
A cracked tone wheel will cause a fault code, turn on the ABS light, and deactivate the ABS system. If it continually activates at every stop, every time you stop, the tone wheel is intact.

Choice 1: pull the ABS fuse
Choice 2: replace both wheel bearing assy's
Choice 3: remove sensors without breaking them, grind away rust, dont get crud into the bearing, (put a tire valve stem cap into the exposed hole), treat metal with anti rust paint, reinstall sensors and hope it's fixed.

Question: Does it pull one way when the ABS activates? If so, replace the bearing assy opposite of the way it pulls. I.E., if it pulls right, the ABS thinks the left is locking up, so ABS pulses the left. Replace the left bearing assembly.

FYI, I've got the same basic truck, though not nearly as shiny. '00 Denali, 5.7, all black and those sweet chromey 16's. New York's salty winters and 206,000 miles have dulled the paint, but nothing a few hours with a DA buffer couldn't fix.