Brake Pedal going to the floor...

[Fuzzlet]

After 2 sessions at yesterday's club track day (all of 10 laps), the brake pedal was going to the floor. After a quick bleed of the front brakes she got a bit better, but by the end of the day pedal was getting closer and closer to the floor. I'm going to give the system a proper bleed thismorning, but was wondering if anybody out there might know what the problem could be? Im running dot 5.1 (elf), with hawk HP+ pads and DBA rotors

[JBT]

Dead fluid
Boiling fluid
Air in the system
Water vapour in the system
Leak (external or internal)

[hks_kansei]

Personally I think it's fluid fade (boiled)

Pad fade = pedal is stiff, not much slowing happening.

fluid fade = pedal goes to floor, not much slowing happening.

[Hammer]

As HKS suggested, it could be over heating brake fluid.

But also check your brake lines, as there could be a very tiny leak.

[Guran]

Sounds like the fluid is ready to be changed out. Which type of Elf fluid are you using? I've been recommended to try Elf HTX 115 which appears to be DOT 5.1. CT tells me he flushes his every six months and bleeds it after each event.

[CT]

Make sure you bleed with the ignition turned on and the sequence from longest lines to shortest lines for ABS cars. It is also highly possible that your technique for opening and closing the bleeders is letting air back in. If you use the Elf HTX fluid and the car is properly bled, you should not be having this problem.

[stevesports]

Make sure you bleed with the ignition turned on and the sequence from longest lines to shortest lines for ABS cars. It is also highly possible that your technique for opening and closing the bleeders is letting air back in. If you use the Elf HTX fluid and the car is properly bled, you should not be having this problem.

i thought for ABS cars, you don't need to follow the route from the longest brake lines to shortest lines?

[Fuzzlet]

Re-bled the brakes thismorning, and the pedal seems to be alright, but not 100%. I definately think its bleeding method thats to fault - I use speedbleeders, and most ppl who've used them then ditched them because of these problems....

[Guran]

Another vote for the old two-person up-down technique!

[JBT]

.........or take it to a brake place that can pressure bleed the fluid through the system.

[Hellmun]

.........or take it to a brake place that can pressure bleed the fluid through the system.

It sounds like the fluid system, when my pedal could hit the floor I found bubbles and basically a broth in my master cylinder. That was overheating. I had it pressure flushed down in Wollongong by Brakesmart and immediately could foot my foot to the floor on track...but it still didnt' pull up. So then I changed the pads and I finally had reliable brakes. Until I got faster again.

I've changed the fluid twice since by myself though and not had problems. If your trouble shooting and not confident, I'd just get them pressure flushed by someone who knows Mazda's. Luckily CT knew a heap of places in wollongong to suggest. Not sure who's good up in Sydney.

[Fatty]

i've had no problems with the speed bleeders on my na6 so far. maybe the abs complicates things ?

anyway, i've had all sorts of problems with my brakes but never had the symptom described, the pedal dropping to the floor. i've had a mushy pedal , warped rotors, glazing, poor braking performance.... etc, but never had the pedal drop to the floor. as others have confirmed, that sounds like you're boiling the fluid. maybe it's just that the fluid is not fresh enough, ie - you need to flush it more often.

anyway after a lot of experimentation i've found something that works for me. i had motul 5.1 fluid but i've ditched that now. i did a full bleed, replaced it with supercheap auto homebrand 'heavy duty" dot 4 , replaced the bendix ultimates and advances (tried them both) with hawk hp+, and my brakes now perform a lot better. i also fitted new oem front rubber lines, and replaced all the rubbers etc, using one of those rebuild kits from mx5parts. (should be no need to do this on a newer car like yours)

i know using cheap fluid sounds crazy, but i really do prefer the supercrap dot 4 over the motul 5.1. the pedal and brakes just "feel"better and the car definately stops better now. the motul stuff is very expensive... the supercheap stuff is , well, super cheap so i just give the brakes a good , thorough bleed before every track day. it's like $6 a bottle..... i probably go through 4 or 5 bottles more per year, but this seems to work better for me than a $40 bottle of fluid. i go through a lot more fluid but in the long run i have better braking performance and it's probably cheaper this ways too.

in short, keep the fluid fresh, maybe even bleed it between sessions at the track (speed bleeders help here).

anyway, this seems to be working for me. your mileage may vary. maybe i should put my flame proof jacket on before i hit the "submit" button

[rossint]

I've been through the speedbleeder problem which caused the pedal to go to the floor. For me the problem was the bleeder not seating properly in the caliper (the taper at the bottom NOT the thread). I fixed the back by undoing them and re doing them a few times and this seemed to rectify the problem, I couldn't get the fronts to seal up though. When I upgraded my front brakes the bleeders sealed in the new calipers no problem. It's pretty easy to see if you have the same problem as I had, take the dust cap off the bleeder, if it's full of fluid the bleeders not seating properly and allowing fluid out and air into the bleed hole. I still run speedbleeders on all 4 corners and my brakes are now rock solid.

[TieNN89]

Make sure you bleed with the ignition turned on

just wondering

does it not bleed properly with the ignition turned off?

[CT]

Re-bled the brakes thismorning, and the pedal seems to be alright, but not 100%. I definately think its bleeding method thats to fault - I use speedbleeders, and most ppl who've used them then ditched them because of these problems....

SPEEDBLEEDERS = LEAKS

Ignition opens the valves in the ABS unit to let any trapped air escape into the lines so it can be bled.