• Mustang Forums
  • 2005 - 2014 S-197 Mustang -General/Talk-
  • 2005 - 2009 Specific Tech

brake fluid all over.....

  • Thread starter Thread starter mustangmike6996
  • Start date Start date Jan 30, 2007

mustangmike6996

5 Year Member
Nov 10, 2005
483
6
29
clinton twp, MI
Jan 30, 2007
#1
  • Jan 30, 2007
  • #1
anyone with a s197 and a brake fluid leak on the master cyl. i was told by ford(who talked to someone in the tech center) that this is due to depressing the brake and clutch pedal at the same time from the excess pressure build up. the tech center recomended that the dealership remove some of the brake fluid almost to the minimum fill line.

has anyone else been told this same line... it sounds reasonable
 
T

thump_rrr

New Member
Nov 25, 2004
220
0
0
Montreal, Canada
Jan 30, 2007
#2
  • Jan 30, 2007
  • #2
mustangmike6996 said:
anyone with a s197 and a brake fluid leak on the master cyl. i was told by ford(who talked to someone in the tech center) that this is due to depressing the brake and clutch pedal at the same time from the excess pressure build up. the tech center recomended that the dealership remove some of the brake fluid almost to the minimum fill line.

has anyone else been told this same line... it sounds reasonable
Click to expand...
They are full of crap.
The gaskets suck plain and simple.
Some people have cut the lids from coffee cans or margarine containers and put a layer below the factory gasket to prevent leakage.
I had my cap replaced twice to no avail.
Pull your inner wheelhousing liner and check to see if the fluid didn't peel the paint off down there.
If it did make the dealer repaint it under warranty to prevent rust.
 

bigcat

start with the upper hole, and if more traction is
May 1, 2005
3,015
1
79
7200 feet
Jan 30, 2007
#3
  • Jan 30, 2007
  • #3
many people have had good results with removing some of the fluid. i removed some of mine, and have not had any leaks in a few months.
 

mustangmike6996

5 Year Member
Nov 10, 2005
483
6
29
clinton twp, MI
Jan 30, 2007
#4
  • Jan 30, 2007
  • #4
i have already had it in for this concern 3 times. (lemon law????) just making it official. it ate the paint off of the frame rail they resprayed it under warranty. i even told the service advisor some of the cures for repairing the leak when i took it in today. i havent let the brake fluid get too far out of my control since the respray.
 
N

NorthwestGT

New Member
Jan 11, 2006
177
0
0
Pasco, WA
Jan 30, 2007
#5
  • Jan 30, 2007
  • #5
I think you guys should badger your dealer to fix the leak under warranty. That is the only thing that worked for me. They replaced my brake fluid reservoir and it has not leaked since (more than six months so far). It is a defect in the moulding of the top of the lip where the cap is supposed to seal.

Mustangmike, I had to take mine back to my Friendly Ford dealer twice before it was clear to them that there was something more to the leak problem than just a dirty seal in the cap. But, they finally did the fix.
 

kooldawg6

mine works really well and can take a fair amount
Aug 31, 2006
1,679
2
38
Central VA
Jan 30, 2007
#6
  • Jan 30, 2007
  • #6
mustangmike6996 said:
anyone with a s197 and a brake fluid leak on the master cyl. i was told by ford(who talked to someone in the tech center) that this is due to depressing the brake and clutch pedal at the same time from the excess pressure build up. the tech center recomended that the dealership remove some of the brake fluid almost to the minimum fill line.

has anyone else been told this same line... it sounds reasonable
Click to expand...


That certainly is funny since mine is the automatic and did it as well...I too took the cap off, cleaned the cap and bottle real well and removed some fluid. No probs since(been about 3 months).
 
W

Warlok

New Member
Oct 11, 2006
89
0
0
Jan 31, 2007
#7
  • Jan 31, 2007
  • #7
YUP!

NorthwestGT said:
I think you guys should badger your dealer to fix the leak under warranty. That is the only thing that worked for me. They replaced my brake fluid reservoir and it has not leaked since (more than six months so far). It is a defect in the moulding of the top of the lip where the cap is supposed to seal.

Mustangmike, I had to take mine back to my Friendly Ford dealer twice before it was clear to them that there was something more to the leak problem than just a dirty seal in the cap. But, they finally did the fix.
Click to expand...

I noticed the same thing on the top of the lip. I just took an exacto knife trimmed the top edge just enough to flatten the ridge and it seals perfectly. I never removed any fluid.
 
N

NorthwestGT

New Member
Jan 11, 2006
177
0
0
Pasco, WA
Feb 1, 2007
#8
  • Feb 1, 2007
  • #8
Warlock, you know I was going to do that but I chickened out. Didn't want to risk getting any chips in the fluid. But, that is exactly the problem, bad seal from irregularities on that lip.
 

cowtown

Founding Member
Nov 4, 2001
228
0
16
Victoria, BC Canada
Feb 1, 2007
#9
  • Feb 1, 2007
  • #9
Great tip guys, I'll have to do that. They replaced my cap last fall but I'm sure it didn't help.
 

mikeelia

New Member
Mar 31, 2005
39
0
0
SoCal
Feb 2, 2007
#10
  • Feb 2, 2007
  • #10
Someone on one of the forums came up with another solution, which was buying a $.79 round neoprene gasket at a hardware store, and placing over the existing rubber seal [in the cap]. I did that and it seemed to work, though lowering the level of fluid a little seems like a good idea too.

I also heard of one person that put a rag in the reservoir then sanded the MC lip smooth and that worked for him. I think the xacto method is pretty similar.

Mike E
 

metroplex

Member
Sep 7, 2003
405
1
16
SE MI
Feb 4, 2007
#11
  • Feb 4, 2007
  • #11
Wrapping the neck with teflon tape 3-4 turns will also fix the problem. My GT started seeping fluid the day it arrived from Flat Rock, MI.
 

mustangmike6996

5 Year Member
Nov 10, 2005
483
6
29
clinton twp, MI
Feb 4, 2007
#12
  • Feb 4, 2007
  • #12
i have tried the xacto trick and i am waiting for results. i just needed to get my car in there a few (3) times and have the paperwork showing that i have had this issue before, then if there is another problem in the future with the dealership being rediculous ill just make them eat the car and give me a new one.
 

jay07

Member
Aug 3, 2006
81
2
9
Feb 5, 2007
#13
  • Feb 5, 2007
  • #13
I looked at my resevoir over the weekend and it doesn't seem to have any burrs and seems to be a pretty flat surface. How noticable is the uneven surface? I don't think mine has leaked yet, at least not to my knowledge. Any tips on identifying the defect?
 

metroplex

Member
Sep 7, 2003
405
1
16
SE MI
Feb 5, 2007
#14
  • Feb 5, 2007
  • #14
If yours has not leaked, it won't leak. My Stang leaked the day it came home with 2 miles on the odometer (had just arrived from Flat Rock). Luckily I caught it and wrapped the neck with teflon tape for the time being. I may try the exacto knife method to smooth the top of the neck. Alternatively I may buy a new reservoir and true the neck surface and just swap the entire reservoir. I believe they just pop in/out?
 

metroplex

Member
Sep 7, 2003
405
1
16
SE MI
Feb 18, 2007
#15
  • Feb 18, 2007
  • #15
Update: I took a careful look at my reservoir. Previously, I wrapped the neck with teflon tape and it did not melt. However, the teflon tape was soaked with brake fluid.

I looked at the seal surface of the reservoir and cannot see how it is malformed or a "defect". The ridge appears to be part of the molding or design. A soft gasket is designed to form itself to minor irregularities, and this ridge is just designed to further improve the sealing.

I think there are several things in common with the various fixes:

Using a rag stuffed in the reservoir to prevent plastic chips from falling in while smoothing out the neck. This may soak up or absorb some of the brake fluid in the reservoir.

Having the dealer swap reservoirs several times until one no longer leaked. It's possible the fill level was different, with the most recent reservoir not filled as much as the others resulting in the leak being fixed.

Lastly, the obvious solution is to remove some of the brake fluid from the reservoir.

There's a slit cut in the center of the gasket, and if the fill level is too high, some of the brake fluid can shoot right through this slit, onto the back of the gasket, and drains out through the cap. That's my theory at least.

A fix would be a revised cap gasket with a smaller slit, or the center piece located MUCH higher to prevent sloshing brake fluid from seeping through the slit.
 

Mark25

Member
Jul 30, 2006
93
0
6
Virginia Beach, VA
Feb 18, 2007
#16
  • Feb 18, 2007
  • #16
I took some cotton tubing (my wife gets them at a nail salon) and cut two one and half inch pieces and place each piece at opposite ends under the cap (front one facing the radiator) and the other piece facing the firewall...I use a flat tip screwdriver to get them shoved under the cap...it's been 9 months and I haven't seen a drop of brake fluid anywhere...the cotton must be absorbing any excess that comes out.
 
You must log in or register to reply here.

Similar threads

1970 brake issue. Bad booster or?
  • All Stock93
  • May 13, 2025
  • 1965 - 1973 Classic Mustangs -General/Talk-
Replies
10
Views
689
1965 - 1973 Classic Mustangs -General/Talk- Sep 13, 2025
All Stock93
R
Brake Master Cylinder replacement steps for 2016 S550?
  • Reybeast
  • Dec 16, 2024
  • 2015 - 2023 (S550) Mustang -General/Talk
Replies
1
Views
480
2015 - 2023 (S550) Mustang -General/Talk Dec 21, 2024
89ripper
E
Finished my Fox Hydroboost Install - Tips
  • Engineer Duane
  • Apr 9, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
4
Views
1K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- May 5, 2025
Engineer Duane
E
C
5r55s auto to TR3650 Manual swap 4.0 V6
  • Ceskz
  • Feb 24, 2025
  • 2005 - 2014 Specific V6 Tech
Replies
7
Views
1K
2005 - 2014 Specific V6 Tech Mar 27, 2025
89ripper
For Sale 3-owner 1987 Mustang GT, $18K obro, Lancaster CA
  • Bill Cool
  • Oct 6, 2024
  • Fox Body Mustangs For Sale (1979-93)
Replies
4
Views
2K
Fox Body Mustangs For Sale (1979-93) Oct 13, 2024
nickyb
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 2005 - 2014 S-197 Mustang -General/Talk-
  • 2005 - 2009 Specific Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?