Having the long brake pedal travel/low brake pedal mystery problem

I don't even know how to start this because after reading loads of old threads on this issue it seems like its just an absolute mystery whenever it happens. The problem is it takes way to much travel in the brake pedal for it to start actually slowing the car down. Completely smooth for almost over half the distance and then firm, not spongy. Pumping it some helps a little, but not as much as I've seen in other threads with this issue. This has happened before, and my dad took it in to a shop and they completely rebuilt the rear brakes to try and fix it which worked a little? Maybe getting new shoes helped. Yesterday I decided to fix the parking brake which had been wonky for as long as I can remember, and adjusting the nut on the handle and the bell cranks it seems to have brought the problem back. When I had the problem before, it was in conjunction with the parking brake being far too loose, and I tried the brake shoe adjustment back then and it didn't do anything. So far I've only troubleshooted 2 things, and that's the brake shoes are currently properly adjusted, and I don't seem to have any other symptoms of a failing master cylinder. Also, I'm not sure but the shop must have flushed the brakes when rebuilding because the brake fluid looks quite clear, don't know if that's just something you do. But this was over 6 months ago at this point so who knows if there is any air, but it really doesn't feel like it at all. Something else the shop did before the rebuild made the brake pedal feel better but it also made it so when you push it all the way down it started making a horrible vibrating noise. That's when my dad took it back and they rebuilt the brakes. (If you're wondering we are never going to that shop again.) I've also read about vacuum lines being a possible culprit, we actually had those replaced chasing an EVAP code recently. Honestly I'm really hoping I'm just overestimating what's wrong it turns out I just need to adjust some other nut.

Edit: My 4runner is a 2002.

I just fixed this problem on mine last week. My brake pedal would pretty much have to go to the floor before it would start braking. I did everything I could think of. Rebuilt the rear brakes, changed all the soft lines to stainless steel, got a new OEM master cylinder, and bled it a ton. Turns out my issue was the ABS pump. Went to a junkyard and got one and the brakes immediately improved after putting it on. I had no codes or anything telling me it was bad.

toverturf said:

I just fixed this problem on mine last week. My brake pedal would pretty much have to go to the floor before it would start braking. I did everything I could think of. Rebuilt the rear brakes, changed all the soft lines to stainless steel, got a new OEM master cylinder, and bled it a ton. Turns out my issue was the ABS pump. Went to a junkyard and got one and the brakes immediately improved after putting it on. I had no codes or anything telling me it was bad.

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If this is it then I don't know if I have the skillset to replace it. Unless it's easier than I'm thinking. Trying to google where the ABS pump even is and it's just showing me pictures of the entire master cylinder assembly. Is it the metal cylinder next to the reservoir or something else?

Dragon_EX said:

If this is it then I don't know if I have the skillset to replace it. Unless it's easier than I'm thinking. Trying to google where the ABS pump even is and it's just showing me pictures of the entire master cylinder assembly. Is it the metal cylinder next to the reservoir or something else?

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What year is yours?

toverturf said:

What year is yours?

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Sorry, I should have said it in the post. 2002.

Same exact problem man but I just gave up after the drum adjustment. I do remember my dad telling me the ABS started to act very erratic one time and heard a strange "pop" noise or something similar. Mine bites really hard but it's a long travel. I'm sure my ABS pump is the issue and could be yours too.

My 2002 is the same. Did the 210mm Tundra brake mod and its super soft on the first and second push. hardens up after a few but a pain.

I tried everything. bled it multiple times, got the auto bleed caps, used techstream to bleed the abs..... still sift brake pedel. Kinda gave up.

Dragon_EX said:

Sorry, I should have said it in the post. 2002.

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Your ABS pump is integrated with the master cylinder so it's a lot of money. Only 2001-2002 4Runners have the same ABS pump/master cylinder setup.

Bad Luck said:

Your ABS pump is integrated with the master cylinder so it's a lot of money. Only 2001-2002 4Runners have the same ABS pump/master cylinder setup.

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Is there any way to test it? Or is it one of those you only know once you replace it kind of things.

I know this is going to make me sound like a dick (I don't mean to). But
Please take this truck to a professional, before someone gets hurt. I've read both your post. It sounds like you may have multiple small problems now from not following proper procedures. Let a pro get you sorted out and safely back on the road. Sorry.

Dragon_EX said:

Is there any way to test it? Or is it one of those you only know once you replace it kind of things.

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There are test procedures, but the equipment/software required would be at a Toyota dealership and some independent shops may have it as well.

calicojax said:

I know this is going to make me sound like a dick (I don't mean to). But
Please take this truck to a professional, before someone gets hurt. I've read both your post. It sounds like you may have multiple small problems now from not following proper procedures. Let a pro get you sorted out and safely back on the road. Sorry.

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Don't worry, I understand the concern because I'm concerned in the exact same way. If it means anything I never ended up messing with the brake adjustment like I said on my last thread because, besides not trusting myself, it seemed unnecessary and also kind of dangerous if it was over adjusted. My 4runner isn't my primary transportation either, it gets driven once a week if lucky. But yes, I am going to take it, probably to the dealership near me, not just because of this but because the shop my dad kept taking it to really did a number on it, not just the stuff with the brakes but they also replaced one of the old cheap catalytic converters it had and did the worst welding job I've ever seen. And when we took it back they just smeared Permatex everywhere. Really destroyed my trust for franchise mechanics. And yeah, the timeline is weird and complicated and it's hard to convey through text but I never intended to do anything myself mechanically that involved more than adjusting some screws or nuts which is what I was hoping would fix this. The next time I drive it it will be to take it to the dealership. Also didn't mean to turn this reply into an essay but what can you do.

Dragon_EX said:

Sorry, I should have said it in the post. 2002.

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Yea your master cylinder and abs pump are all integrated into one and it's about $2200 for a new one. The ABS pump on my 1999 is $1100 new so that's why I got a junkyard one. I don't know what to tell you about yours since a 2002. I'm not familiar with how it all works. Hope you get it fixed though.

Yeah that shop sounded sketchy in your other post. It wouldn't surprise me if they used the cheapest Chinese crap for parts. So it's possible the shoes wore out in a few months. Especially if they didn't replace the drums or have them turned. The stealership maybe a bit pricey. We have great members here. Someone here is from your area (where ever that is.) and knows of a good shop. We should be able to get you hooked up.

I'll try and remember to update this thread once it's fixed or at least diagnosed because it seems like this is a common issue and the cause is almost always a mystery. Hopefully it can even be figured out (without torching my wallet in the process). It seems like a lot of people go through the effort of doing things like bleeding the brakes over and over, replacing the master cylinder, replacing all the brake lines, rebuilding the brakes (like my dad had done), and it still never got resolved so hopefully I can get to the bottom of this.

Alright, here is the update, just for posterity so anyone else who googles this can see. As a quick spoiler, this turned into a cautionary tale against franchise mechanics more than a troubleshooting post. I just got my 4runner back today and all I have is good news. I did end up going to the dealership but I think it turned out great. Seems like I got lucky and didn't end up at a stealership. In the end I'm not exactly sure what out of what they did fixed it but the brakes are back to perfect feeling. As a refresher/clarification, the shop I had taken it to before kind of fixed it by rebuilding the rear brakes. Got it maybe halfway to perfect feeling. Then I mess with the parking brake and it goes back to feeling like garbage, and flat out unsafe to drive. Honestly still not sure if it was a screw up on my part, the shop's awful work, or something inherent.

First of all, it turns out that the axle bearing and the seals on the driver side were shot, the tech emailed me a picture of everything inside the drum dripping with grease... Not particularly surprising however, because the passenger side one failed a couple years ago and was making the drum smoke so it was only a matter of time, but I'm glad both are fixed now (what the hell did the other shop do to when they rebuilt the brakes?!). Next they did a full brake job and flush, turned the drums and got new shoes, and they ended up deciding to do a front brake job as well, but I don't feel ripped off because the last time the front pads got replaced was probably 5 years ago, my dad got cheap ones and I don't even think he got the rotors turned. So yeah, the brakes feel really great now, back to exactly how I imagine it should feel. OEM parts probably help with that too.

As you can probably guess going to the dealership was not the cheapest at $1300, those labor costs rack up, but I don't even care at this point. It's probably the most annoying problem I've had with my 4runner just because of the way it made driving feel less safe. I swear the brakes must have felt like that for several years. I thought for sure the whole time they were gonna call me back and say "yeah its the master cylinder, that'll be $4000 please", and even after they told me about doing the full brake jobs and flush I thought "oh, its just standard procedure I'm sure, I'll have to take it back for that $4000 master cylinder replacement", so I'm honestly extremely happy to have the brakes back to normal. Unfortunately I don't see this update helping many people in the future since it turned out to be a simple and obvious brake job that fixed it, so it's turned more into another cautionary tale about how typical franchise shops screw you over. So in the end I guess the moral of the story is, if you gotta take your 4runner to someone to get it fixed, make sure they know what the hell they're doing! Who would have thought? And as a funny side note, the first thing written on the paperwork is "inspect the drivers floor mat" twice. They must get a lot of those kind of people coming in...

Sounds like your dual master cylinder has worn into a single.

Meaning, it sounds like the MS is worn out.