Brake Pulsating - ABS?

[ArkGuy]

Hey guys,

I used the search function but didn't see this specifically - apologies if overlooked.

Bought a brand new 2012 last week. I believe this problem was present from the get-go, but my wife drove it first so I didn't get to feel it.

There is a 1-second very rapid pulsating in the brake pedal when coming to a stop. Happens in all situations - cruising at 50mph and applying light pressure, when braking to shift from reverse to drive, when coasting at 25mph and applying pressure to slow down.

Does not happen only when 'firm' pressure applied, happens when the pedal is barely suppressed in advance of actually applying the brake. I've taken it to two different dealers (bought in AR, live in Chicago). One has told me twice it is normal (went back a second time to drive a different 4runner, which they did not have, and have a tech ride with me). The other dealer felt the issue, but cannot discern the cause due to: 1) no computer light registers, i.e. no code to read 2) no other 2012 4Runner available to compare against 3) no Toyota bulletins speaking of issue.

Does anyone else have this issue? I do not believe it is normal. I'm in a holding pattern now until I can actually find another 2012 to compare against and see about getting it fixed, so far little help other than 'it's normal'. Which, if it is, that's fine, I just want it to be the way it should be.

Thanks in advance for the help.

 

[adam2562]

i think i know what you're talking about.. its nothing that has concerned me though. its like a slight shudder in the pedal RIGHT when you apply it? i think it's something that they're gonna do and we have to deal with it lol

 

[ArkGuy]

re

Well, it feels more like I'm stepping on a phone in vibrate mode. Always lasts about 1 second, and is always rapid. It doesn't happen every time, probably about 50%. It's much more noticeable in low speeds. It also happens if I'm at a complete stop and apply a little extra pressure. Think if you're reaching for your wallet and don't want to let your foot off the brake

 

[Jtraskell]

Well if this helps at all, I am very certain this is NOT normal.....be safe.

 

[ArkGuy]

thanks for confirming..now just need someone who is willing to fix it or figure out how to fix it.

 

[kmiller8821]

thanks for confirming..now just need someone who is willing to fix it or figure out how to fix it.

Try your Toyota dealer.

 

[ArkGuy]

I've tried two in the area, but no dice..keep saying it's normal or can't compare it to another 2012, so they are unwilling to try anything until they do so. driving me mad.

 

[mikebontoft]

Hmm that's something a dealership should do with a customer complaint such as this. They need to let you drive another 2012 to see whether or not it is a "characteristic" of the vehicle ("normal" isn't a good word )

 

[ArkGuy]

just a bump -

made an appointment with a different dealership on Saturday to get it looked at, wanted to see if anyone else had any thoughts as to what this is. From the replies and also from the lack of replies, I'm convinced it's not normal

 

[mikebontoft]

I'm not convinced of either. Find one to test drive...

 

[roadracer30]

The only time I notice anything like this is when my foot is on the brake and I start the truck. It vibrates for a second, like a cell phone, right as the truck is starting. If I am not pressing the brake when I start the truck, but just have my foot resting enough to feel the pedal, this doesn't happen.

Maybe that will help track it down?

 

[Eagle]

ArkGuy, have a question / test for you -- if you have your truck running, but completely stopped (like at a stop sign or even just sitting in park) hit the brake once then quickly hit it again and leave your foot on there... (basically apply, release briefly, then apply softly and hold). Does that give you the same thing you're describing?

 

[M1911]

Sounds like the brake booster. My '03 4Runner has been doing that since it was new. I've now got 120k on it.

Yes, it is normal.

 

[ArkGuy]

Eagle - It does do that. I've noticed when sitting at a stop light, if I let the brake up to inch forward, then push it down to stop again, it engages this one second vibration.

RoadRacer - yes, thats exactly how i would describe it, as a cell phone, only it does more than just the initial time.

As an update, stopped by another dealer today on the way home from work. They had a 2012 Limited in stock, so while mine is an SR5, I figured if it did it on the Limited, I could expect it on mine as well. It did the exact same thing on the Limited.

I was kind of surprised about it. I didn't see any chatter about it on my internet search before posting. It isn't something i've ever experienced in a vehicle before and I figure others would think the same and post questions online.

I asked the service guy to just give me an overview of what's happening, mainly because I was curious. He said basically the ABS is testing itself (I'm paraphrasing) when braking, even on dry surface, in case the vehicle does encounter a slippery surface, it will be 'charged' up and ready to take it on.

I was relieved when the Limited did the exact same thing as mine, so now I can quit worrying about it and just enjoy the drive!

 

[mikebontoft]

Good to hear

 

[BlackWorksInc]

It sounds like normal operation of the braking system. the 4th & 5th gen 4Runners utilize a hydraboost unit that uses hydraulic pressure vs. conventional vacuum assist. You'll feel the pump kicking in regularly as it maintains pressure in the accumulator, it will kick on when you first start the vehicle after depressing the brake pedal a couple times, holding the brake pedal, ect. as long as its a very slight vibration and noise its normal.