SN95 To Fox Swap. Brake Problems!

brodymac

New Member
Jan 2, 2020
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London Ontario Canada
Hey Guys, new to the site. I recently did a SN95 Spindle swap on my 93 Fox. I upgraded to 94 GT calipers on the front and left the stock rear drums. I’m getting mixed findings about whether I have to upgrade the m/c and booster or not. I have a very soft pedal. They hardly work and I have bled each of them many times... I’m hoping it’s something I can fix without upgrading anything else. I added a pic of the car just because
 

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nickyb

WAIT,you now have a pair?
10 Year Member
Apr 3, 2009
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You should be ok ,unless you let the master cylinder run out of fluid when you changed things? If so you let air in there and now you need to bleed the master.that should do the trick.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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polk county florida
This may help you out.
There is also a discussion on mc bore size and why it is important to have the right mc for the calipers and the relation with drum/disc brake setups. I'll see if I can find it. Meanwhile one of the members may chime in with their thoughts.
 

Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
36,174
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Massachusetts
The 66mm calipers on the 94 GT are about 20% larger than the stock 60mm fox units. That means without an MC swap, your pedal stroke is about 20% longer giving you a softer pedal, and longer stroke.

If you change to the 99-04 GT aluminum calipers (use same rotors, need some slight spindle clearancing) , they are about 10% larger than 60mm fox units.

If you change to 99-04 Cobra calipers and 13" rotors, they are 10% smaller giving you a slightly firmer pedal

I would make a decision to change your front setup to one of the above. Without swapping to rear disk, it's the best you will get.