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Abs brakes

hello all! i have a 98 chevy tahoe and the truck seems to make a strange noise sometimes when applying the brakes.
i can feel (sorta) the noise in the brake pedal. is this something that needs a scan to find out where it’s coming from?
is it an expensive fix? tia.

Does this happen more than once a drive? They can make a noise upon first application.

Brakes can make lot’s of noises, most of which during normal braking indicates it may be worth taking it to a specialist. Brakes are one of those things I don’t mess and guess with. From the info you gave, I wouldn’t 'count on anyone here being able to give you a difinitive answer. That you “feel” something as well may indicate it’s time for a little brake work.

This May Or May Not Have Anything To Do With The ABS System. It Can Be As Simple As Worn Brake Parts, But Difficult To Say Based On The Limited Description.

Usually, but not always, you’ll get an ABS warning light if that’s an issue. Then the car should be scanned for ABS codes. A code reader/scanner capable of reading those codes is usually needed, as a regular engine/transmission reader won’t do it.

Questions: Are you getting any warning lights, ABS, Check Engine, or otherwise ? If so, explain.
Have the brakes been inspected or replaced in fairly recent history ?

CSA

Are you getting any warning lights, ABS, Check Engine, or otherwise ? If so, explain.
Have the brakes been inspected or replaced in fairly recent history ?

no warning lights. i get a funny sound like a bleating animal, sorta. i had rear brakes replaced recently for inspection but the noise was happening before that. a few years ago (i forgot to mention before) this happened and i had to have replaced a front sensor attached to a hub, i think it was called. i think they had to scan to find the correct wheel. i think it was one of the front wheels. sorry but i forgot about the past episode.

A sound like “a bleating animal” could be an indication of problems with the vacuum brake booster. Have your mechanic check for leaks from the booster.

What’s the weather been like where you live?
If the roads have been at all slippery, ABS can and will make a “bleating” sound as it functions that you can feel as a pulsation in the pedal. Been there, done that.

It sounds like what happened a fe2w years ago was that a bad wheel speed sensor was telling the ABS computer that you had a wheel slipping and the same symptom occurred. It sounds like they changed the wheel speed sensor. If that’s accurate, than perhaps you have another bad sensor or a dirty sensor. If you drive your truck over dirt roads, sandy roads, or something of that type, it may be prone to getting the sensors dirty. If not…well, it IS getting old. An occasional bad sensor ain’t a big price to pay.

A wheel speed sensor system is basically just a segmented ring with an inductive sensor that counts the teeth as they fly by. The frequency of the signal it sets up tells the computer how fast the wheel is turning. If that gets crudded up, or the sensor gets old, it can malfunction. And, sincethe system has no comparative signal to validate the input, it can do so withuot tripping an ABS light.

yeah but it only has 70 k’s on it!

May or may not be your problem but I have seen alot of this as a gm mechanic. Google 02-05-25-006b,this is a technical service bulletin that applies to your vehicle.

thanks, i read the bulletin and i think i have the problem explained in the read. are they only in the front wheels or all 4?

only on the front wheels

Chevy pickups, Suburbans, Tahoes and vans of this era had notoriously bad abs systems. I drove Suburbans and vans for a school system after I retired from trucking and the only time our mechanics were done working on the brakes was when they were sold.