Whine/Squeal that changes with braking

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

chatt100

chatt100

SILVER Star
10 Year
Joined
May 15, 2013
Threads
18
Messages
265
Location
Chattanooga, TN
I have a 99 100 that has started a high pitched whine/squeal coming from behind the steering wheel, it mostly occurs shortly after starting. Sometimes it will stop with pumping the brakes however returns shortly after. If it does not go away with braking it becomes less intense with braking. Lasts for a min or two and then decrescendo's to a high pitched squeal and goes away. Does not change with acceleration. Any ideas on what this could be? I'll try and get a recording the next time it happens.
 
Could be the 'squeal tabs' on the brake pads indicating you may need new pads and possibly a rotor.


Official Jeep Recovery Vehicle
 
So diagnosis mad. All the fluids were fine. The sound happens even when in park and had the rotors/brakes recently changed. My father-in-law who is a mechanic took a listen and its the ABS modulator.
 
Ok another question. Now I'm having more issues. The initial sound I described has continued to happen. Now intermittently the ABS/Brake light will come on and the alarm will sound. It only lasts for a few minutes. The brakes work fine throughout this, they do not go to the floor and are not spongy. As I said before the brakes have been changed, rotors turned, fluid flushed and changed in the past month. I have not been able to run a code check while the abs/brake light is on yet. Hopefully I will catch it next time. I'm guessing this is something in the electrical system somewhere. Could both problems be related to a wheel sensor? What other than running a code check should I do?
 
You shouldn't have to wait until the light is on to run a check. The code should remain stored in the computer. That being said, when you hear the sound, have you opened the hood and listened to the booster unit on which the brake fluid reservoir sits? That's the power brake booster unit, and the little cylinder that sits on top houses the accumulator. Sometimes these things go out and will make a whining noise. There are many threads on this board about this unit and the problems others have had with them, and I think I recall reading one where the accumulator can be either rebuilt or replaced. Otherwise, you have to replace the whole brake unit, and new Toyota units are outrageous. On the other hand, Cruiserparts.net might have a used one......

Just my initial thoughts.
 
Ran a code check, nothing came up. When the brake/abs light is on it does sound like there is a whine coming from the brake booster unit. If it was going/gone out would/could all of this happen intermittently?
 


Audio isn't great but here is the noise. When it is happening the brakes work fine and no warning lights are on.
 
Sounds like the pump, that pressurizes the rear brakes has some failing bearings.
 
You must log in or register to reply here.

Share this page

Back
Top Bottom