im driving less then 20 mph and i break, and i push the pedal to the floor

whats the cause of this? im thinking the caliper are dead , break fluid is fine. i also was bleeding the calipers too then i drove and the break pedal is to the floor

 

You should not be on the road.

Your problem has very little to do with the calipers, it has to do with the hydraulics .. master-cylinder, ABS modulator, hydraulic lines and the slave cylinders.

It could be as simple as bleeding the system. Farthest slave to the nearest from the reservoir.

In a properly working system, with one foot all the way on the brake (fully depressed), the other toe should be able to go under the pedal.

Salim

 

It might be the brake booster or master cylinder. Does the pressure/resistance build up again if you pump the brakes?

 

yes..wheres the master cylinder

 

I am all for DIY projects, but with all due respect, you may be over your head
[You may be fully qualified to do it, but my impression is based on the 2 posts here]

Master cylinder is affixed to the reservoir. The reservoir feeds the fluid directly to the master cylinder.

Salim.

ps: I have experienced total brake failure and consider it my good fortune that there was no loss of life, limb or material. Get help from a friend or mechanic.

 

DO NOT DRIVE IT IN THIS CONDITION !!!!!!!!!! If your not able to fix it,have it towed to a reputable shop a.s.a.p!

 

no worried i been learning to fix cars my whole life..and learning from every aspect of it..

but yea the car is just sitting in the drive till i get a master cylinder

 

sounds like you have gotten air in the lines, how exactly did you bleed the brakes?

 

It's not air, your master cylinder is bad and it's located right below the reservoir. That metal unit with the various metal tubes running out is the master cylinder. You'll need to replace that whole part, but there essentially is a small piston inside that pushes fluid through the lines to your brakes. Like any pistion, it has rings and they deteriorate with time and unfortunately, not much warning except what happened to you. Some times, the warning is catastrophic in nature, especially if you need to stop in an emergency.

Replace it, fill with fluid, and bleed the system. Not a very difficult DIY job, but should take a good few hours with assistance to bleed.

 

Alex, why do you insist the master cyl is bad, were the brakes working before he bled them, we don't know..... if he was bleeding them and got air in the lines he would have the same problem. When troubleshooting a system, the first question the tech/mech/engineer...take your pick asks is what is the last thing you did before the failure. By advising him to replace the master cyl. without knowing all the details is just making lots of work....... don't be an alarmist..... do the easy stuff first..... I asked him how he bled the brakes.... yes its easy, but its also easy to suck lots of air in if you don't do it right. Also the ABS system makes it a bit trickier..... but not that difficult. So, krazy, go back check your work, and if that does not restore you brake system then go for it.... tear into your master cyl, out of curiosity how many miles are on the car....good luck, just remember, KISS......it is a lesson that I have learned over the past 60 years of turning wrenches, fixing exotic electromechanical, electronic equipment, and computers.

Capn

 

That's true CaptFred, you should always go with the least expensive check first... then move on to the more expensive. The master cylinder is probably going to run you $90-$120, so if it's air, you can get that out with two bottles of brake fluid.

I doubt it's air only because the pedal shouldn't go down to the floor if he's stepping on it. After bleeding, once you've pumped up the pressure, then with air you should feel sponginess in the brakes, not just "boom" to the ground.

Another check, once you build up pressure, keep you foot on the pedal, does it stay or graduallly go back down to bottom? That's another test to see if master cylinder or not. Anyway, as the Capt. said, try the fluid again and see how that goes.

 

theres no air in it. i bleed from FL,FR,RL and then RR..but still it push to the floor.

goin to replace the master cylinder

 

wrong.

pass-rear, driver-rear, pass-front, driver-front. Each point till the stream is clear.
see my post #2 in this thread.

Salim

 

Yep, that's the way I did mine in late 2007.

 

let us know what happens...... sounds like you may have probs with the master, I had the same situation,, mine was a blown line ......right rear... LOL...... came up to a stoplight, hit the binders,,, and whooooooa, to the floor alice....... carefully drove home using the handbrake,,,,, had my gf push the pedal,,,, saw a puddle forming.....pulled the wheel... and there it was a split..... but my first reaction was Master Cyl........ good luck

capn