Brakes went out this morning! HELP!

[Kanine21]

Hello,

(2003 2WD 4Rnr, V8)
My wife called me this morning on the way to work saying her ABS/TRAC and VSC lights light up (no CEL) and a loud alarm sound was going off. Hoping it was a low fluid level, I asked her to pull over and pump the brakes a little bit and if the brakes and pedal felt ok, she said they felt normal. She continued to drive and as she was cresting a small hill and started to apply the brakes, she said the pedal felt solid as if she couldn't push it and the car was not stopping.
In a panic she ripped into a 76 station and applied the parking brake and had to slam it in park. Luckily she wasn't going too fast, but traffic was stopped in front of her.

I turned around and came to check it out. The alarm was still going off, all lights were still on and the pedal was rock hard. As I tried to drive it slowly back and forth, pressing hard on the pedal barely seemed to do anything with the brakes.

Luckily we were only 1.5miles from home, so I had her drive my car and I followed her home keeping it in Low gear, hazards on and using the parking brake while using the regular brake to see it anything would change.

As we were coming up our street, I applied the brakes and BOOM, they starting working fine. They grabbed like brand new and were working great, BUT, the ABS/VSC/TRAC lights were still on as well as the Alarm was on the whole way home.

We parked it at home and I took her to work.

What the hell could it be? ABS pump? Master cylinder? Pressure sensor? Accumulator?

I flushed the fluid and refilled with DOT4 about 3 months ago when I replace the front rotors and rebuilt the front calipers. I'm confident those are fine and it's something to do under the hood.

Any help would be greatly appreciated!

Kane

 

[radlynx]

That's scary! If she was on the highway at highspeeds, that could end up in a tragic accident. Good thing she was quick and safe. I am not sure what caused it but one of those must be starting to fail. Keep the distance!

Hello,

(2003 2WD 4Rnr, V8)
My wife called me this morning on the way to work saying her ABS/TRAC and VSC lights light up (no CEL) and a loud alarm sound was going off. Hoping it was a low fluid level, I asked her to pull over and pump the brakes a little bit and if the brakes and pedal felt ok, she said they felt normal. She continued to drive and as she was cresting a small hill and started to apply the brakes, she said the pedal felt solid as if she couldn't push it and the car was not stopping.
In a panic she ripped into a 76 station and applied the parking brake and had to slam it in park. Luckily she wasn't going too fast, but traffic was stopped in front of her.

I turned around and came to check it out. The alarm was still going off, all lights were still on and the pedal was rock hard. As I tried to drive it slowly back and forth, pressing hard on the pedal barely seemed to do anything with the brakes.

Luckily we were only 1.5miles from home, so I had her drive my car and I followed her home keeping it in Low gear, hazards on and using the parking brake while using the regular brake to see it anything would change.

As we were coming up our street, I applied the brakes and BOOM, they starting working fine. They grabbed like brand new and were working great, BUT, the ABS/VSC/TRAC lights were still on as well as the Alarm was on the whole way home.

We parked it at home and I took her to work.

What the hell could it be? ABS pump? Master cylinder? Pressure sensor? Accumulator?

I flushed the fluid and refilled with DOT4 about 3 months ago when I replace the front rotors and rebuilt the front calipers. I'm confident those are fine and it's something to do under the hood.

Any help would be greatly appreciated!

Kane

 

[radlynx]

check this out. http://www.toyota-4runner.org/3rd-gen-t4rs/45949-freaky-brake-problem-morning.html

 

[radlynx]

can you provide the details as to what the weather is like during the incident? some has mentioned that it can be the check valve.

so when you pressed the pedal, does it stop slowly or nothing at all even if you pressed it hard?

So here's what I think.

If it's the check valve, you'll be able to slow down by pressing the pedal very hard.
If it's the brake booster, you should be able to slow down as well by pressing it hard.
If it's the master cylinder, you either loose pressure and the pedal goes all the way down.
If it's the ABS pump, you might get those errors and have a hard pedal.

 

[Kanine21]

can you provide the details as to what the weather is like during the incident? some has mentioned that it can be the check valve.

so when you pressed the pedal, does it stop slowly or nothing at all even if you pressed it hard?

So here's what I think.

If it's the check valve, you'll be able to slow down by pressing the pedal very hard.
If it's the brake booster, you should be able to slow down as well by pressing it hard.
If it's the master cylinder, you either loose pressure and the pedal goes all the way down.
If it's the ABS pump, you might get those errors and have a hard pedal.

Typical beautiful San Diego weather, slightly over-cast, high-60's, dry, low humidity.

I press the pedal and it's as if it's locked and BARELY moved. It went down maybe 1/2" if that, not halfway as normal.

When I pressed it as hard as I could it would BARELY slow the vehicle, if at all.

Once we were headed up my street on the way home all of a sudden they worked fine, as if they were normal. But the ABS/VSC/TRAC lights were all still lit along with the alarm constantly on. So something is still definitely wrong.

When I flushed the fluid, I put in Valvoline DOT4 synthetic fluid. Any issues running synthetic in these systems? I can't see that being an issue, unless the check valve or something would have seals get eaten up by the fluid? I would think petroleum based fluid would be more damaging, but I don't know.

Thanks!

Kane

 

[radlynx]

Check this out again. It must be your ABS pump. BRAKE FAILURE pedal hard to push - Toyota 4Runner Forum - Toyota 4Runner Enthusiasts Forum

Typical beautiful San Diego weather, slightly over-cast, high-60's, dry, low humidity.

I press the pedal and it's as if it's locked and BARELY moved. It went down maybe 1/2" if that, not halfway as normal.

When I pressed it as hard as I could it would BARELY slow the vehicle, if at all.

Once we were headed up my street on the way home all of a sudden they worked fine, as if they were normal. But the ABS/VSC/TRAC lights were all still lit along with the alarm constantly on. So something is still definitely wrong.

When I flushed the fluid, I put in Valvoline DOT4 synthetic fluid. Any issues running synthetic in these systems? I can't see that being an issue, unless the check valve or something would have seals get eaten up by the fluid? I would think petroleum based fluid would be more damaging, but I don't know.

Thanks!

Kane

 

[Kanine21]

Check this out again. It must be your ABS pump. BRAKE FAILURE pedal hard to push - Toyota 4Runner Forum - Toyota 4Runner Enthusiasts Forum

Ugh.... Spendy. Found one on ebay for $850 obo. It's the whole assembly so it'd be an easy swap.

Asked my brother too since he works at a salvage yard.

Hopefully I can pull some codes with my scanner tonight and see if it points my in that direction.

Thanks! Kane

 

[BlackWorksInc]

Ugh.... Spendy. Found one on ebay for $850 obo. It's the whole assembly so it'd be an easy swap.

Asked my brother too since he works at a salvage yard.

Hopefully I can pull some codes with my scanner tonight and see if it points my in that direction.

Thanks! Kane

Use a scantool that talks ABS, you need to pull the DTC history from the Skid Control ECU. Hopefully this will give us an idea of what direction to go in.

How did you bleed/flush the system when you reinstalled the calipers? Did you clamp off the brake line or did you leave it open for a while? Is it possible air may have worked its way into the hydraboost unit?

 

[Kanine21]

Use a scantool that talks ABS, you need to pull the DTC history from the Skid Control ECU. Hopefully this will give us an idea of what direction to go in.

How did you bleed/flush the system when you reinstalled the calipers? Did you clamp off the brake line or did you leave it open for a while? Is it possible air may have worked its way into the hydraboost unit?

I opened the system and flushed the old fluid to the bottom of the reservoir. Once I noticed it was almost empty, I then filled the res with new fluid and kept pumping it through until the fluid looked clean coming out of the bleeder valves.

It's totally possible I got air in the system as shortly after I did it and bled the system, these lights came on. I added more fluid and bled them again and the brakes felt fine and all the lights went off. It been fine ever since mid July when I did it. Then all of a sudden this morning without warning, this happened.

Did I fry the pump motor? :-(

Kane

 

[BlackWorksInc]

I opened the system and flushed the old fluid to the bottom of the reservoir. Once I noticed it was almost empty, I then filled the res with new fluid and kept pumping it through until the fluid looked clean coming out of the bleeder valves.

It's totally possible I got air in the system as shortly after I did it and bled the system, these lights came on. I added more fluid and bled them again and the brakes felt fine and all the lights went off. It been fine ever since mid July when I did it. Then all of a sudden this morning without warning, this happened.

Did I fry the pump motor? :-(

Kane

Difficult to determine this early on. We need to see if there is any DTC history stored in the Skid Control ECU. Which means you may need to go to the dealership and/or a shop that has an ABS capable scantool that can speak Toyota if you don't have one.

It could be as simple as an air bubble to as catastrophic as a failed unit. :shrug:

 

[Kanine21]

Difficult to determine this early on. We need to see if there is any DTC history stored in the Skid Control ECU. Which means you may need to go to the dealership and/or a shop that has an ABS capable scantool that can speak Toyota if you don't have one.

It could be as simple as an air bubble to as catastrophic as a failed unit. :shrug:

Thanks for all the tips. I just got home and tried scanning it, nothing came up. I don't think my little Bluetooth scanner has the abs capability although it reads every other sensor on the car it seems, lol.

So as soon as I started it up, the lights were still on and the alarm was going. I pumped the brakes to a 40 count. During that time I could hear the pump motor buzzing away off and on intermittently. While pumping I also noticed the pedal would either stick or be normal, back and forth. As I got closer to 40 pumps, the pedal felt normal for the last 10 pumps or so and all of a sudden the lights and alarm went off.

I popped the hood and listened to the abs pump motor, it was kicking on and off again and slowly kicked on less and less until it stopped.

I hopped back in and felt the pedal for another 20 pumps. Felt normal. I slowly put it in reverse, then drive back and forth testing the brakes. They were grabbing very well.

I won't let my wife drive it until I have complete confidence, but should I drive it to Toyota tomorrow and have them scan the skid ecu? I'm afraid they might come back saying all these codes that I need a new pump assembly when it may have just been a weird bubble?
Safety and piece of mind are definitely worth the $800, but we're really hurting for cash due to some medical stuff lately so it's pretty hard to come up with it.

I'm going to go test drive around an empty street later when traffic dies down.

Thanks again for everybody's time and suggestions. Hopefully I can figure it out.

Kane

 

[BlackWorksInc]

Yeah, most aftermarket scanner will not communicate with ABS and other factory modules such as SRS unless you upgrade/buy the more expensive models. OBDII is supposed to be standard across the board, which is why you can have cheap scantools that read only OBDII codes. But manufacturers build their vehicles with two halves, OBDII and Factory.

 

[Kanine21]

Just drove it around for about 20 minutes and it drove fine. I went up and down hills at various speeds, tapped the brake pedal several times quickly and hard stops, rode the brakes down a hill, panic stopped trying to trigger the abs. It all worked perfectly. :noidea:

Kane

 

[zonianbrat]

Scan it at a dealer. May not be the news you want to hear but it isnt worth blowing it off then having a loved one hurt or worse in a car accident. This is after all how your vehicle stops!

 

[radlynx]

Have you heard of intermittent problem? sometimes it's there, sometimes it's not there. that's you case. If it happened once, it will happen again at the most inconvenient time. it's all now in your hands. :kiss:

Just drove it around for about 20 minutes and it drove fine. I went up and down hills at various speeds, tapped the brake pedal several times quickly and hard stops, rode the brakes down a hill, panic stopped trying to trigger the abs. It all worked perfectly. :noidea:

Kane

 

[Red]

Take it to a dealer, you need a certified Technician to inspect your entire brake system.

Definitely stop driving it around like a Russian roulette crash test dummy.

 

[nevada]

I won't let my wife drive it until I have complete confidence, but should I drive it to Toyota tomorrow and have them scan the skid ecu? I'm afraid they might come back saying all these codes that I need a new pump assembly when it may have just been a weird bubble?Kane

highly unlikely, its a sealed high pressure system. unless it has a leak somewhere, and is able to draw air in.

also, none of what you described is a symptom of air.
it sounds like the booster is failing, or worse. take it in, stop driving it. you're going to cause an accident.

Take it to a dealer, you need a certified Technician to inspect your entire brake system.

Definitely stop driving it around like a Russian roulette crash test dummy.

this.


and hahaha

 

[Kanine21]

I drove it to work this morning so I can take it to Toyota this afternoon. I definitely need to get it checked out. It's just weird that it went away so quickly once I pumped the brake system. I too am afraid it'll rear its ugly head at the worst time. I'm definitely not just going to forget about it.

Kane

 

[DC runner]

You also realize that you could be opening up a whole slew of legal crap if an accident occurs.

Driving around in a vehicle with a now known history of brake failure basically means your committing a degree of negligence in continuing to drive it. If your brakes go out and you hit another car and injure or kill someone (that vehicle is very heavy) and they are able to determine that you were aware of the problem and continued to drive it..... that is serious.

Hell, if I found out the sob that just hurt my family was basically "oh to hell with it, lets just gamble" and didn't immediately halt driving the vehicle, have it towed to the dealer to be professionally inspected, I would basically force the courts to push for the max sentence if there was any hint of negligence.

Driving is a privilege and you are bound by basic human decency to do everything in your power to NOT expose other humans to undue risk. You continuing to act as an above poster said " a Russian roulette crash test dummy" doesn't just endanger you ( I wouldn't care it you were the only one at risk, have at it) but it threatens everyone else on the road near you.

Stop driving it. I have a small child and this kind of crap just burns me up.

 

[Kanine21]

Took it to the dealer yesterday and they pulled no codes at all. They said there is an ecu re flash needed under recall which they performed. The tech personally talked to me and said to him the brakes felt a little squishy. Not bad, but he bled the whole system and said there was no air in the hydro boost system, but further down. There must have been air in the hydro boost system at the time of the occurrence. The pressure sensor must have been in that bubble briefly and caused the misreading and the whole issue.

He tested the pump, sensor and all electrical components including relays, fuses and pump motor. Used the scan tool to bleed the system using the pump as well and recalibrated the endpoint once done. I drove it around the parking lot and didn't really notice a big difference in pedal feel, but there was a difference.
He said I wouldn't notice hardly any difference if air were in the hydro boost system as much as I would if it were in the caliper or further down in the brake lines. Made sense.

I asked him if pumping the brakes like I did most likely moved the bubble, he said yes as none were in the hyroboost canister anymore, it was further down in the lines by then. Now the whole system is air free.

Now, for all you coming down on me for driving it, yes I drove it, yes I had flashers on at all times, yes I had my left foot on the brake pedal at all times, yes I had my right hand on the gear shift at all times, no I did not go above 20mph, no I didn't pass any school zones or populated areas, or rural areas, or any roads that had hardly any traffic at all. It was pretty much all industrial park areas at hours where nobody was on the road.

I truly understand your concerns but you have to realize I was very conscious of where I was and on edge at all times. I acted as if I expected the brakes to fail every time I came to a stop. I basically drove as if I had no brakes and crawled everywhere. I know this is no consolation to many of you, but if you were in the car with me, you'd realize how safe I was. I'm not one of those *******s that does 50mph through a school zone flipping off kids while running over cats snorting coke.
The pope mobile would have honked at me and flipped me off for driving so damn slow.

Thank you all for your tips and advise. I'll continue to drive it for a few more days before handing the keys back over to my wife.

Kane