3rd Gen Spongy Brakes (Again)

Yes, I have read lots of threads on this, but I don't see exactly what I am trying to nail down.

Basically, the initial inch or so of brake travel has made a "squishing" sound ever since I bought it with 4,000 miles. After that squish, the pedal was mostly firm like you'd expect for a truck. Bleeding the brakes helped a little, but not a whole lot. One possibility I've read is that poorly adjusted drum brakes can have long travel that would explain everything, some threads have suggested adjusting them, but mine are supposed to be automatically adjusting when slowed in reverse. I obviously reverse frequently, so maybe I just need to play with harder braking a couple times in reverse? Or look elsewhere for the issue? Or is this simply a case of They All Do That. I'm not against that being the answer, just want to be sure there's not something that can be done first. I've never had an issue with braking strength, and I frequently tow.

 

You got any friends or coworkers with a third gen you could take around the block?

 

Not immediately, but the sound is very clearly audible. If it is something that is common, you'd hear it.

 

Is it a squishing sound or a squeak? Not my brake pedal, but the clutch pedal in my truck started making a low squeak a few months ago. They use a plastic bushing on the clutch pedal assembly, not sure about the brake pedal pivot.

As far as spongy goes, does yours have the electronic brake booster? My trd offroad does, and the first half inch or so of brake pedal travel has always felt squishy, then as you press past that point you can hear/feel the brake booster kicking on and it begins to feel like a normal brake pedal after that.

I recently swapped to 4runner front brakes, and that 1/2" of squishy travel is now slightly longer (larger pistons, has to move more fluid) but feels firmer and more responsive, and definitely brakes faster as the booster engages.

 

My 2nd gen and two 5th gen 4Runners that I’ve drove all make the squish noise when applying the brakes. Probably something to do with the electronic brake booster on some models assuming you have an OR.

 

Definitely a squishing sound. Sounds like brake fluid being pushed quickly through an orifice. Funny you mention the clutch bushing - I had that happen with my 2ZZ-powered Elise a while back. This is definitely not that though.

Mine sounds and feels just like the brake system somewhere has some mechanical slack that has to get taken up before the brakes really engage. Once the slack is taken up, the brakes are firm and strong enough. Not grabby by any means, but plenty sufficient.

I'm perfectly fine with there just being some slack in the system - they all do so some extent - I just want to make sure I am not ignoring something under warranty that could be a sign of something worse

 

Yes, I do have a TRD OR

 

Sorry, that doesn’t help with the other portion of your issue if you have spongy brakes. It’s important to note that the drums self adjust when activating the e-brake and not by driving in reverse. Definitely not a bad idea to take the drums off from time to time to clean the debris in there and check adjustment but I’m not sure if that’ll help if that’s something you’ve felt from new.

 

Ok, offroad with the electronic brake booster- I had similar experience with regards to noise at first. If at low enough speed for tire noise to be minimal I can hear what sounds like the piston moving in the master cylinder in that initial slop/travel before the booster kicks on.

It took me a bit to get used to it, as that first bit of pedal travelnis definitely moving the pistons in the calipers, but it doesn't really feel like its enough pressure to bite and slow the truck. I've had to get used to that initial, I guess I'd call it sponginess, push slightly past it to get to "normal" linear brake response. Especially noticeable at low speeds, like in parking lots and stop and go traffic.

Have you noticed the noise getting any louder with time, or if you're in traffic and using the brakes frequently?

 

It's weird, it feels exactly like the drum shoes (or caliper pads) are sitting far off and need the first bit of travel to contact the drum (or rotor). My BMW would do that on purpose and described the feature in the user manual. That car would use a pump to draw the pads away from the rotors when driving along, and then it would pre-apply the pads to the rotors if you lifted off the gas quickly enough. You could really tell a difference - the pedal had this same initial travel as my Tacoma if you didn't lift quickly. If you did, it would be firm at the top of travel. I wouldn't be surprised if the truck is also doing that to some extent, but google says it is not, or at least not with an active system like the E91 did.

It’s not bad at all, just noticeable if the radio is off and windows are up. I just think it is interesting there seems to be no mention of it here unless people are confusing it with soft brakes.

 

Tacoma brakes took a while to get used to when I got the truck, gf would always complain about the brakes until she got a 4Runner and realized that’s just how these vehicles feel. Would definitely be a big change if you’re coming from a Lotus and BMW.

 

I thought there was a TSB or Campaign for a squishy brakes, however I can't seem to find it. My pedal is a lot firmer than my friends Tacoma for what that's worth.

 

The brakes are plenty firm *after* the initial slop, it’s just I can’t find out if the initial slop is normal or not. Like with the BMW, the manual gave an explanation for the initial uptake, so I could live with it. It’s just strange that a truck sold in such volumes as a Tacoma doesn’t have a more solid answer here either way

 

Searching for TSBs came up with no TSBs, but it did bring up this thread:

https://www.tacomaworld.com/threads/new-2023-tacoma-potential-brake-issue.791891/

he says the whirring went away with time, but the whirring is different from the hiss (I can hear both and separate phases). Not sure if the hiss was ever changed