Weird sound from ABS

Hi there everybody, I've used the site quite a bit over the last year or so but this is my first time posting. Thanks for all the great discussions and info!

I've got a 2004 DC I bought back in September '22, and since the first time I heard it kick in, the ABS has always acted weird. For one, it seemed too sensitive to me, kicking in during obvious situations (icy roads etc) but at such low speeds it didn't seem necessary. Two, when it did kick in I always felt like I was basically unable to decelerate, not a great result from a system designed to help you stop in low traction situations. And three, it makes a weird sound, sort of a springy sigh rather than the tap-tap-tap I'd expect.

I took it into the dealer thinking, at a minimum, that the sensors could be bad and that's why it's so sensitive, but they drove it around with the computer (or so they told me) and all the sensors looked good. Of course they couldn't do much beyond that since it's hard to activate the ABS on command.

Well then I was towing our small travel trailer (~3k lb) and exited the highway on a ramp with a bit of gravel due to construction. I hit the brakes, ABS kicked in, and I just rolled right through the intersection. After that I turned up the trailer brakes but I'm pretty sure they were already the only thing slowing me down.

That when I became certain something was up. I knew I needed to capture what the ABS is sounding like and ask everyone here about it. I found a speed bump I could hit pretty hard while braking to kick in the ABS. Unfortunately, the sound of hitting the speed bump is a lot louder than the sound of the ABS right after, but I'm hoping you can still hear it. Here's the video.

The brakes have always been a little soft (and they are really soft when I'm in 4WD for some reason), but from reading on the forums I figured that was normal. But now I'm suspecting maybe something up with the master cylinder? Though not sure why it would only kick in during ABS activation.

Thanks for any help the collective wisdom can offer!

 

I dealt with this for a long time before giving up and pulling my ABS fuses. I was getting random ABS activation at low speeds. Replacing the wheel speed sensor didn't help. Cleaning the tone ring did not help.

Have you determined which wheel is having ABS activate? That would be step one. Then you can pull that sensor and try to clean it. Peek in the hole and inspect the tone ring for any dirt or debris.

 

Hey thanks for the reply, but like I said I had the sensors checked and they seemed to be signaling correctly (could always be intermittent I guess). After reading a bit I e sort of accepted that the tundra ABS can be sensitive and that isn't even necessarily a bad thing. My main concern now is that when the ABS 'activates' it's not actually even doing what it's supposed to be doing. Unless that sort of sighing sound is how all tundra ABS systems sound? In other vehicles I've had it's always been a tapping sound.

 

That sound did not seem normal to me but it can be hard to tell in videos. If it caused you to roll through an intersection that doesn't sound safe. I would pull the fuses.

 

What you describe sounds 'normal'.

I deactivated my ABS...it tried to kill me one too many times driving down my road in the winter.

And frankly, ABS is bad technology, doubles stopping distance on snow and ice and causes an overall increase in road deaths. It is NOT designed to help you stop, this is a common fallacy. It's designed to help you STEER, at the expense of stopping. Each tire only has a certain total traction budget, it can use that budget for stopping, accelerating, or steering, or any combination, but once that budget is spent, the wheel slides. All that ABS does, is partially disable braking, to free up more traction for steering. If your total traction is very low because you are on ice, gravel, snow, etc....this means you get little to no braking, as steering is always going to be given priority by your witless ABS system, even if its so slick you can't steer either. A locked tire provides the most possible braking force in soft surfaces..but ABS doesn't care. It just wants to keep those tires rolling no matter what.

Going downhill on ice, the ABS kicking in will actually cause you to GAIN speed and go faster and faster until you turn off the engine to kill the ABS and stop the old fashioned way. (why I still have my truck, although I thought I was going to die of a heart attack the first time that happened to me, nothing is as terrifying as standing on the brake while your truck speeds up headed for a tree)

One of the things about modern life that just fills me with rage if I think about it too much. One of the greatest frauds ever forced on people.

However, I do have one important question: How well does your parking brake work? The parking brake on our trucks is more important than most realize, as it controls the rear brake auto-adjusters and can give you an overall soft brake feel if not working properly.

 

Do a search for 1st Gen ABS solutions. Might have even found this on Tundra Solutions. I had a similar problem and found a way to limit inappropriate ABS incidents.

The solution: My ABS module is under front passenger seat. I glued several washers together and then glued them under the ABS module, effectively tilting it to one side. It has eliminated about 90% of the inadvertent incidents for almost five years now.

Simple, but it works. It changes the yaw angle to compensate for any additional lift.

 

Out of nowhere my ABS started acting up like yours a couple years ago. It will give you some pucker up moments especially when your on a dry road and expect to stop but keep on going. I just did as the other members did and pulled the fuses. Good luck and welcome

 

Here's a video @Cz24 shared on another forum concerning the ABS problem.
Hell of a sound when it happens.

 

On my truck the ABS pump is on the passenger side, while the Master Cylinder is on the driver's side (of course). There are 4 brake lines that run across the top of the firewall between the two, secured by plastic clips. The clips become very brittle with age. This video sounds like one or more of the hard lines is loose, and banging on the firewall when the pump kicks on.