Manual Transmission T56 | T5 | MN12 | Clutches | Hydraulics | Shifters

Master Cyl Failure

Thread Tools
 
Search this Thread
 
Old 11-27-2007, 01:49 PM
  #1  
TECH Fanatic
Thread Starter
iTrader: (8)
 
tee-boy's Avatar
 
Join Date: Apr 2007
Posts: 1,165
Likes: 0
Received 0 Likes on 0 Posts
Default Master Cyl Failure

what is the number one reason a MC fails? Is it basically the seal erodes/corrodes and therefore it no longer effectively forces fluid into the stainless line? Or is it maybe the return spring that fails? Or is it maybe the lines get clogged w/ solid material and therefore no fluid movement?
Old 11-27-2007, 04:14 PM
  #2  
TECH Enthusiast
iTrader: (3)
 
JonB's Avatar
 
Join Date: May 2005
Location: Orange Park FL
Posts: 704
Likes: 0
Received 3 Likes on 3 Posts
Default

A combination of things, condensation(aka water in the system), deteriated fluid, air in the system, normal wear and tear. On your car which I get from your sig is a 98 that means that master is 10 years old now. How many times in 10 years has that pedal been depressed? I'm gonna guess in the millions over 10 years. The o-rings inside the master rub inside twice every time you depress and let the pedal back up. Although they are lubed with brake fluid over years of use they will eventually wear causing problems after all they are only rubber.

Now if you've changed your master a few times already and looking for a solution I would look into keeping your fluid clean and fresh and air free.
Old 11-27-2007, 06:54 PM
  #3  
TECH Fanatic
Thread Starter
iTrader: (8)
 
tee-boy's Avatar
 
Join Date: Apr 2007
Posts: 1,165
Likes: 0
Received 0 Likes on 0 Posts
Default ddd

cool, but what is the number one reason for failure... Spring, Seal, Clogged ports?
Old 11-28-2007, 12:40 AM
  #4  
11 Second Club
iTrader: (12)
 
TARZAN's Avatar
 
Join Date: Dec 2003
Location: Memphis Area
Posts: 1,312
Likes: 0
Received 0 Likes on 0 Posts

Default

My guess would be (if you had to choose ONE thing) worn out fluid.

-Will
Old 11-28-2007, 07:23 AM
  #5  
TECH Fanatic
Thread Starter
iTrader: (8)
 
tee-boy's Avatar
 
Join Date: Apr 2007
Posts: 1,165
Likes: 0
Received 0 Likes on 0 Posts
Default ddd

Originally Posted by TARZAN
My guess would be (if you had to choose ONE thing) worn out fluid.

-Will
worn out fluid is not a failure! Worn out fluid is a cause of a failure.
Old 11-28-2007, 07:37 AM
  #6  
TECH Senior Member
iTrader: (23)
 
brad8266's Avatar
 
Join Date: Aug 2005
Location: Watertown, NY
Posts: 8,797
Likes: 0
Received 0 Likes on 0 Posts
Default

The primary reason for master cylinder failure is pitting/deterioration of the bore surface in the cylinder, which leads to the internal seals tearing on the pits edges as they travel across the pits. This is accelerated by old worn fluid and moisture in the fluid.
Old 11-28-2007, 08:19 AM
  #7  
TECH Fanatic
Thread Starter
iTrader: (8)
 
tee-boy's Avatar
 
Join Date: Apr 2007
Posts: 1,165
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by brad8266
The primary reason for master cylinder failure is pitting/deterioration of the bore surface in the cylinder, which leads to the internal seals tearing on the pits edges as they travel across the pits. This is accelerated by old worn fluid and moisture in the fluid.
Thanks. I probably could have figured that out if I was from Hattisburg, MS. Home of the Golden Eagles!!
Old 11-28-2007, 09:51 AM
  #8  
11 Second Club
iTrader: (12)
 
TARZAN's Avatar
 
Join Date: Dec 2003
Location: Memphis Area
Posts: 1,312
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by tee-boy
worn out fluid is not a failure! Worn out fluid is a cause of a failure.
lol, thats what I was saying. You asked what was the #1 cause of failure, and I guessed the #1 thing that causes failure would probably be worn out fluid, seeing as how it can contribute to multiple different failure enducing problems

-Will



Quick Reply: Master Cyl Failure



All times are GMT -5. The time now is 05:58 PM.