I know a few of you Fox guys are looking at doing this conversion in the future so I thought I would post my experience.
As some of you know, last winter I did the SN95 4 wheel disc brake conversion on my 89 GT. I had left the brake booster install for another time. Some people claimed that it wasn't a neccessary step. I have to disagree. The braking is very much improved, but the pedal was very hard. I've had the booster sitting around for a while now and decided it was time to tackle the job. I'm happy to report that it was pretty straight forward and also a success!
I unbolted the MC and moved it out of the way. You can leave the lines connected and bend the unit out of the way gently. I then removed the driver's seat and got up under the dash for a while getting those 4 stupid booster bolts out. I figured out how to get some long extensions on 3 of those suckers and zipped them out fast. The 4th one takes some time and you can only use a wrench. Did I mention that there isn't any room under there?
The stud pattern is just a little different between the boosters and some light grinding with the Dremel was needed to open up the holes in the firewall. A few test fits and I was in!
Back under the dash I put on the new nuts and washers (can't use the Fox ones, different diameter). Right after that I hit my only snag. Installing the stop light switch was a snap, but the back of it would get hung up on a brace and wedge when you stepped on the pedal. Hmm, WTF? Back to the laptop to do some research.
I found out there is a difference in the booster arm that goes to the pedal. Some are straight, some are curved. Stock is curved and mine was straight. The flat part of the arm is where the switch rides. Since the arm was angled down so was the flat. This made the switch hit and bind. Let me rephrase that, the wiring harness connector hit, not the switch body.
I pulled the wires out of the connector and pushed them over the terminals. Voila! I got the clearance I needed!
Buttoned everything back up and the pedal feels like it should now. I can't wait to get it out on the street!
Here's a pic of the different boosters
I used a few differnt sites for reference;
http://www.mustangmotorsport.com/underhood.html
http://www.duggerracing.com/techtips/brakes/index8.shtml
http://www.mustangcentral.net/tech/brake.html
As some of you know, last winter I did the SN95 4 wheel disc brake conversion on my 89 GT. I had left the brake booster install for another time. Some people claimed that it wasn't a neccessary step. I have to disagree. The braking is very much improved, but the pedal was very hard. I've had the booster sitting around for a while now and decided it was time to tackle the job. I'm happy to report that it was pretty straight forward and also a success!
I unbolted the MC and moved it out of the way. You can leave the lines connected and bend the unit out of the way gently. I then removed the driver's seat and got up under the dash for a while getting those 4 stupid booster bolts out. I figured out how to get some long extensions on 3 of those suckers and zipped them out fast. The 4th one takes some time and you can only use a wrench. Did I mention that there isn't any room under there?
The stud pattern is just a little different between the boosters and some light grinding with the Dremel was needed to open up the holes in the firewall. A few test fits and I was in!
Back under the dash I put on the new nuts and washers (can't use the Fox ones, different diameter). Right after that I hit my only snag. Installing the stop light switch was a snap, but the back of it would get hung up on a brace and wedge when you stepped on the pedal. Hmm, WTF? Back to the laptop to do some research.
I found out there is a difference in the booster arm that goes to the pedal. Some are straight, some are curved. Stock is curved and mine was straight. The flat part of the arm is where the switch rides. Since the arm was angled down so was the flat. This made the switch hit and bind. Let me rephrase that, the wiring harness connector hit, not the switch body.
I pulled the wires out of the connector and pushed them over the terminals. Voila! I got the clearance I needed!
Buttoned everything back up and the pedal feels like it should now. I can't wait to get it out on the street!
Here's a pic of the different boosters
I used a few differnt sites for reference;
http://www.mustangmotorsport.com/underhood.html
http://www.duggerracing.com/techtips/brakes/index8.shtml
http://www.mustangcentral.net/tech/brake.html