Brake Master Cylinder Failure? - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Suspension, Brakes, Drivetrain discuss the wondrous effects of boost and your miata...

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 08-21-2009, 03:54 PM   #1
Elite Member
Thread Starter
iTrader: (1)
 
NA6C-Guy's Avatar
 
Join Date: Feb 2008
Location: Birmingham Alabama
Posts: 8,038
Total Cats: 43
Default Brake Master Cylinder Failure?

Up till today I have never had any problems out of my brakes. Was driving back from the book store and went to stop (had just gone through a bunch of stop and go traffic, nothing then)and the pedal went about half way before it caught. Kind of startled me. The rest of the drive was cruising and only had to use them one more time pulling onto my road. It also did it then. I pumped it two or three times pulling in the driveway and the pressure came back. Would a master cylinder just fail like this, especially at only 120k miles? Any of you ever had brake master cylinder problems? I have had cars in the past that have lasted 200-250k miles and never had any brake issues. I start school Monday, and this is really bad timing for another damn problem.

I know the fluid is supposed to be changed with fresh fluid every year, something I have never done on any other car. I would imagine old dirty fluid would lead to seal failure. The fluid is a bit orange, not clear/brown like fresh stuff. I guess maybe a master rebuild and fresh fluid would help...
NA6C-Guy is offline   Reply With Quote
Old 08-21-2009, 04:03 PM   #2
Elite Member
iTrader: (8)
 
Join Date: Aug 2007
Location: Bellingham, Wa
Posts: 2,732
Total Cats: 3
Default

Flush your damn brake fluid with some fresh super blue.
wayne_curr is offline   Reply With Quote
Old 08-21-2009, 04:54 PM   #3
Elite Member
Thread Starter
iTrader: (1)
 
NA6C-Guy's Avatar
 
Join Date: Feb 2008
Location: Birmingham Alabama
Posts: 8,038
Total Cats: 43
Default

Yeah yeah, I will. But that wouldn't cause a problem like I described would it? Sudden pedal loss that comes back with pumping.
NA6C-Guy is offline   Reply With Quote
Old 08-21-2009, 05:29 PM   #4
Elite Member
iTrader: (8)
 
Join Date: Aug 2007
Location: Bellingham, Wa
Posts: 2,732
Total Cats: 3
Default

Yes it can and it will. Do you have a leak by chance? Do you ever have to top off your resrevoir?

Brake fluid wicks up moisture like a tampon in a bleeding vagina. Dirty and moisturious fluid causes weird things to happen with your brakes inconsistently like having to pump them a couple times to regain pressure when the fluid heats up. This happened to me at an autox recently. After flushing the fluid, pedal is rock solid.
wayne_curr is offline   Reply With Quote
Old 08-21-2009, 05:51 PM   #5
Elite Member
Thread Starter
iTrader: (1)
 
NA6C-Guy's Avatar
 
Join Date: Feb 2008
Location: Birmingham Alabama
Posts: 8,038
Total Cats: 43
Default

No leaks, never topped it off and its right at the full level like always. I know shame on me for never flushing it. Like I said I have never payed brakes much attention on my other cars and have never had issues. I just find it weird that it just started all of a sudden like that and wasn't a gradual thing. I will flush it this weekend with some super blue and see what happens. I have had a spongy pedal since I got the car, its just one system I always ignore with cars. Again I know, shame on me. All of the work I have done on the car and I ignore one of the most important systems. I just wish I could afford lines and AX6's at the same time. Thats probably one reason I have ignored them so long. I had plans to upgrade the brakes, but it always gets put on the back burner. I keep telling myself it can wait till I get new pads, rotors and lines.
NA6C-Guy is offline   Reply With Quote
Old 08-21-2009, 06:10 PM   #6
Elite Member
Thread Starter
iTrader: (1)
 
NA6C-Guy's Avatar
 
Join Date: Feb 2008
Location: Birmingham Alabama
Posts: 8,038
Total Cats: 43
Default

Also, when doing the actual flushing of the system, does it matter which bleeder I use to get the old **** circulated out? Don't want to have a pocket of bad fluid left hiding at the end of one of the lines, though I guess the final bleeding will fix that. I would imagine do the LR since its the furthest. I know when doing the actual bleeding for air you go LR-RR-RF-LF (that is correct isn't it?)
NA6C-Guy is offline   Reply With Quote
Old 08-21-2009, 06:31 PM   #7
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

its either a bad master or a bad 1-way valve.
hustler is offline   Reply With Quote
Old 08-21-2009, 06:44 PM   #8
Elite Member
Thread Starter
iTrader: (1)
 
NA6C-Guy's Avatar
 
Join Date: Feb 2008
Location: Birmingham Alabama
Posts: 8,038
Total Cats: 43
Default

Just drove it to the store to pick up some fluid. Seemed fine now, or at least like it normal is. I think it was just the frequent high speed stops and high temps outside today with the no telling how old of fluid. I'm not even so sure that the pedal went any further than usual earlier I think its just one of those things I never realized, and for whatever reason something made it click in my head that "****, my pedal goes nearly half way before the brakes engage". Either way, new fluid will go in tomorrow. If it does in fact act up again, I will just have to shell out for a new master or a rebuild kit, if you can even buy rebuild kits anymore.

Is there adjustment on the pedal for slack at the top of the pedal? Bleeding it may make it go away, but I have about 1'' of travel at the pedal face before the slack is taken up. I know you need a little, but surely not an inch.
NA6C-Guy is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 59 Yesterday 09:00 PM
Leaky Wilwoods mx592 Suspension, Brakes, Drivetrain 1 10-01-2015 01:45 AM
Bad head gasket or ? shooterschmidty Engine Performance 8 09-30-2015 11:28 PM
wiring wideband ground to battery terminal btabor ECUs and Tuning 10 09-28-2015 06:33 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 01:12 PM.