brake pedal goes down to the floor, can't figure out Y ?help?
 

Ok, 2 days ago (coldest morning) i get in my car, brake pedal smooshes all the way down before the brakes stop the car,(wtf is going on!!! they always felt stiff) So i brought it to my friends shop we lifted it.. checked for leaks for 20min... nothing... drained all the fluid out of the brake system filled it up and blead it for about 2 hours....the car drove home, and the brakes felt like crap for the first 5 sec. then they stiffend right up,(20 min. drive home they felt perfect) I was all happy, thinking i fixed it... WRONG, today got in the car brakes felt like crap again...
-when the key is in the "ON" position, and i pump the pedal up it stiffens... but not super stiff, still mushy.
-does this sound like a master cyl problem?

when the car is off your vacuum assist is off because the motor is not on. when you start the car the vacuum kicks in. if it goes smooshy when the car is on then the master cylinder is most likely at fault....

sounds like you have a master cylinder or brake booster problem.

Master cylinder..I just replaced mine...45 min job..dont forget to bench bleed!

only one thing for me to say:
:wall: I sell master cylinders

i understand it could be an "internal" leak, where fluid is getting past seals at points. but...
How do u guys explain the "temp. fix" after i flushed and bled the system,they worked like new for a day...

anymore thoughts...??

after i bench bleed do i have to rebleed the entire system...
-its starting to snow.. and i dont have brakes... this isnt good....

I'm pretty sure this is 80% of your posts..

if that's how I made money id be doing the same thing... but I'm sure his services are greatly appreciated.

I'm sure they are greatly appreciated. No denying that.

But maybe I'm the only one who gets tired of seeing the peeping face over the wall and "i sell x object" in virtually every thread where anyone may even remotely possibly need a part. I mean, everyone already knows he sells everything under the stars..

everything under the stars! LOL
Some one answer my question..

edit: oh yeah i might have an interview for a job in a taxi shop, part-time, pays good and i get to use the shop anytime i want, BUT how the hell am i going to get their in the snow.. with no brakes....

I've once had a std brake new leasing Ford escort. Started in the British Windsor morning: first stop the pedal clunked to floor, pumping brakes became 'on', and no problems afterwards. Changed the car, but leasing company did not believe mee... "no problem they said, such problems do not exist."

The ABS is very complex piping system, too many places for air to hide. What else could it be than air? Brakes do faint if water is in the system as they boil on hard braking. Seals could leak but that most probably be constant.

How about the ABS control. If it detects slippage, it opens that circuit, losing brake pressure on that line. Now if the ABS computer fails, or some seal for the system, would it result in complete brake loss? Any error codes?

If it was known which pipes are constantly pressurized, I would loosen that/those pipes connections in the ABS assy, just to bleed a little.

You are now he proud owner of a nearly full brake booster ?(duff seals leaking fluid to master cylinder side of the unit). :buttshex:

Worth checking - had it on another vehicle of mine (Golf) - as an added bonus - booster rubber diaphragm seal gets nice and slippery/expand from the now "not designed for brake-fluid" presense and it gets sucked right out of the intended place of work - resulting in a replacement booster required (expensive!) :shiner:

Boosters aren't all that expensive, they're like $95 plus a $50 core.
:wall: ........

nah, more like 50%

I do it because
a. it's how I manage to pay for my car
b. there are always new people joining so not everybody realizes that I sell parts
c. A lot of members don't realize just how deep my parts coverage is.
d. it's fun to do and helps my post count

WAAAAAAAAAAAAT?!?!?!?!?!?!?!?!?!?!?!?!

Sure, sure.................... but then again I like to do something useful with my $150 if its at all possible - something like a case of Jack Daniels or something similar? :shy:

he's correct, if the master leaked out from the rear into the booster (not unusual) the booster will need to be replaced :(

Consider the price on an ABS modulator :eek:

You dont follow the mechanics involved or you just wanna rag on a newbie?

What!?

no.. i read it 3 times and still didnt understand, but its not your falt... im a moron.
-i dont have abs... should of said that in my first post... doh!
- just wanted someone to explain to ME what you said, because i dont know how thoes parts work,

.... internetautomart, did that
-what should i do to find out if the master or booster or both should be replaced?

Do you understand why I suggested or not? - not being nasty at all.

ABS has nothing to do with it at all.

Later
AH ok - Master cylinder has a rear seal responsible for keeping the brakefluid inside the master cylinder - if that seal starts leaking (usually slow) the only place the fluid has to go is the front chamber of the booster - leave it long enough (in your case overnight) and if its bad enough, all of the fluid out of the reservoir and the master cylinder will drain out into the booster (read no or low brakes) and the best external inspection will not detect a single leaking drop at all..........

i edited my last post, i know abs has nothing to do with that type of problem, just said that because someone was talking about abs problems

ok but that sounds like both would have to be replaced right?>

Personally would first strip and confirm the situation - if its the problem, then I would guess yes..........

ok, thanx for the info....

anyother Thoughts?

-why the heck is this happening now.. im so close to getting my ve5!!!!!!!

The old car is getting jealous of the new car :gotme:

Master cylinder. Read the chilton stickie on replacement. Or just have the mechanic handle it as you already go to a mechanic anyway. It would seem he would be the one responsible for diagnostics anyway.

:reading: never brought my car to a mechanic once... oh wait, I lie. I had to get an alignment, about a year ago.

Don't tell me you did the work. Because when you mention "we" I assume it means "them". j/k.

why can't we all just get along,... I'm not going to sit here and try to defend myself against someone who has their heart set on picking fights...
-but because I put countless time and hard work into this car (like many others), I feel the need for some appreciation, but obviously I should be looking someplace else for that...

sry but when u said i bring my car to someone to fix, it hurt

I'll take that as a "no" hehe.. Just joking. Did you see the part where I mention MASTER CYLINDER?

yes, thank you

I would suggest taking the time to bench bleed the mc, and bleed the system again as well. Make certain everything is tight. When it's cold and wet, one has a tendency to get impatient. That could cause one to overlook something. Hope this helps.

Aside note: the last mc I replaced I diag'd as bad when I tried to bench bleed it. I closed the system and put pressure to the piston. It leaked passed the seals inside allowing the piston to slowly depress. Yet another reason for a bench bleed.

good idea,
i understand what u mean, it is very cold outside. ill probly do it in the shop, if i can get the car there...
thanx.

E-brake and down shift

Check your spindle nuts and lug nuts while you're at it. If the axle causes the rotors to get off center slightly it'll cause knock-back as the brake pads try to center the rotor again.

in that case the spindles would have a ton of play in them.. right?

another thing to check are your calipers...my pedel went all the way to the ground...replaced the master, and still did it...the 2 bottem pins on my calipers where frozen...check that also...good luck