Brakes went out this morning! HELP!

[BlackWorksInc]

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.

this.


and hahaha

The issue was that he had performed a brake fluid flush and replaced the calipers prior to this issue occurring, which meant some air may have been introduced into the unit. The problem is that while normally air makes the system squishy in most cars, the system could interpret that there's too low a pressure and seal off ports that he is using, i.e. the main port from the master cylinder plunger as if it were going into ABS assist mode.

~

Glad it seems to be working out for you, unfortunately at this point we've ruled out air in the system. Which means if the issue reoccurs it could be something electrical and/or hydraulic related to the unit.

 

[radlynx]

Looks like the ABS system is fine after all. You did what a responsible person is supposed to do and I think that's safe to drive now with all the test that they did. Just don't let air get into the system when flushing the brake fluid.

What i did on my truck when i flushed it is suck all the brake fluid from the reservoir and fill it to the top mark and bled each wheel and keeping an eye on the reservoir. You might need another person to brake on the pedal while you are bleeding it pretty much like this. 1. step the brake. 2. open the bleeder valve for a few seconds until pedal goes down. 3. close the bleeder valve. 4. release the brake. you'll have to do it multiple times. This is how I do it and never had any issue.

Remember, the rear is a little bit different. it uses the pump for pressure. 1. press brake. 2. open bleeder valve for 2 seconds and close it (this will activate the pump and the fluid will flow). 3. release brake. again keep an eye on the brake fluid not to go below halfway.

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

 

[radlynx]

One more I forgot to mention, remember when we have a sink full of water and we drain the water, it creates that funnel vortex. it's the same way as our reservoir, it creates a vortex in there if you drain it too fast. that is why we don't want the fluid to go below halfway. this is probably how you introduced air in the braking system.