Master Cylinder / Booster - replacement.

gcomfx.com

Founding Member

Oct 22, 2002

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Republic, MO

Sep 17, 2007

#1

• Sep 17, 2007

• #1

Well, I guess the Master Cylinder on the car is about gone. Here I was looking to upgrade to a PBR setup and now it might have just been my master cylinder taking a dump.

In traffic the car's brake pedal would slowly drop at each pulse of the cam. Then during a spirited drive, one stop took entirely too much room to bring the pony to a stop.

I noticed my booster was pretty rusty on the bottom when I did the engine swap. Should I change it as well?

Also, should I upgrade any of this stuff while I'm at it? Or just go with stock replacements on everything?

 

gcomfx.com

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Oct 22, 2002

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Republic, MO

Sep 18, 2007

#2

• Sep 18, 2007

• #2

Wow, no one replaces these?

 

divit250r

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Mar 31, 2005

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Columbia City, IN

Sep 18, 2007

#3

• Sep 18, 2007

• #3

Is the pedal hard, but it feels like it's not getting much assist from the booster? That's a pretty sure sign the booster is shot.

Other than that, does it look like the MC is leaking fluid out where it mates to the booster? That's where the piston seals are in the MC, maybe you've got a leaky seal.

Good luck!

 

gcomfx.com

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Oct 22, 2002

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Republic, MO

Sep 18, 2007

#4

• Sep 18, 2007

• #4

No real leak that I can see. I have to pump the pedal, and still doesn't feel right. Sitting in traffic the car would start to creep forward as the pedal dropped a bit each time the cam loped. Guess it could be a vacuum leak as well.

 

gcomfx.com

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Oct 22, 2002

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Republic, MO

Sep 19, 2007

#5

• Sep 19, 2007

• #5

Ordered a Reman-ed Master Cylinder, should be here tomorrow. Wish me luck. I'm pretty sick right now, but Saturday is the local Ford Invasion at our track. So hopefully I can get some brakes going.

 

R.A.T.M.

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Mar 11, 2001

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17

Taylorville, IL

Sep 21, 2007

#6

• Sep 21, 2007

• #6

Has anybody tried to convert to the hydroboost set up from the newer cars?

 

R.A.T.M.

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Mar 11, 2001

96

0

17

Taylorville, IL

Sep 24, 2007

#7

• Sep 24, 2007

• #7

In case anybody is interested, I found this company:
http://www.hydratechbraking.com/forums/viewtopic.php?t=75&highlight=mustang

I don't know anything about them though.

 

go-stang5.0

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Jan 27, 2003

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Glenview,Il

Sep 24, 2007

#8

• Sep 24, 2007

• #8

Yea if you lost boost the ped. would be really hard. If thats not happening its prolly not the problem. But do check for vac. leaks it cant hurt.

 

go-stang5.0

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Glenview,Il

Sep 24, 2007

#9

• Sep 24, 2007

• #9

Also when the car is off is the pedal soft or stiff. If the booster is leaking the pedal will be stiff as soon as you shut off the car. If its ok...you can get a full pedal pump or two in before the pedal gets stiff. If its spongy and soft all the time when the car is off (after multiple pumps) I would say yes the MC is going or you have a leak, or theres air in the system.

 

gcomfx.com

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Oct 22, 2002

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Republic, MO

Sep 25, 2007

#10

• Sep 25, 2007

• #10

go-stang5.0 said:

Also when the car is off is the pedal soft or stiff. If the booster is leaking the pedal will be stiff as soon as you shut off the car. If its ok...you can get a full pedal pump or two in before the pedal gets stiff. If its spongy and soft all the time when the car is off (after multiple pumps) I would say yes the MC is going or you have a leak, or theres air in the system.

Click to expand...

If I pump it a few times the pedal will get stiff. But not for long. I hope to change the MC tonight or tomorrow night. I've never changed one before, but it doesn't look TOO complicated. The car is about to hit 200,000 miles and I've never touched the brake system besides pads and rotors. Even if it's not the MC, I'm sure the new fluid will help.