Brakes Foxbody SN95 Booster install Question


Apr 22, 2005
Sewell, New Jersey
Hey guys,

I’ve read just about everything out here on the SN95 booster install on a Fox. I have an 88 that’s had the whole front end replaced from what I believe was an aero-front year car. I’ve shortened the studs, elongated the holes, and I’ve spent plenty of time trying to wiggle this thing in, but I’m still not able to get this thing in. I’ve come to grips that I’m going to have to clearance my strut tower, and that’s fine. The issue I’m posting about is related to the right side master cylinder stud. In trying to get this thing in, I was hitting different parts of the booster with a deadblow hammer. I pushed the right master cylinder stud through the booster’s case slightly. Can anyone tell me if I’ve compromised this booster and will need a new one? I’m leaning toward yes, but I don’t know enough about them to be able to definitively tell. The last thing I want to do is get this in and have to take it out again. Thanks in advance for your help.


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10 Year Member
Sep 1, 2010
Kearney, NE
Do you have a hand held vacuum pump with a gauge? Pump it up to -16” and see if it holds is my thought.
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Wasn't a pretty sight...and I've got big hands
SN Certified Technician
Mar 2, 2015
The stud does go into the vacuum side of the booster. It could be fixed by welding it or using a bigger nut than the stud and tightening the master cylinder nut until its flush again.

That is also a great idea to test it. Put a vacuum pump on it and vacuum to 16 in.hg. should hold for about 1/2 hour or so at least.

My car fought me with my booster install ( 93 cobra booster ). Found there is a plastic spacer between the firewall and the dash brace inside the car. That piece of junk had cracked and moved into one of the holes and made it almost impossible. The only way I figured it out was by having someone hold the booster outside of the car while I squeezed my big @as in the car with a flashlight and guided it in with a screw driver. PITA and the hardest thing I have ever done on a mustang.

I did take a BFH to the back of my strut tower. Can't even tell. When I replaced the first one things went a lot smoother...but I was worried.


Apr 22, 2005
Sewell, New Jersey
Thank you for your replies guys. I do not have a vacuum pump, but I will see if I can get a hold of one and give what you suggested a shot.

90sickfox, I know how you feel with this. I have read a lot on this install before going into it, as I know how much of a pain it is. I tried getting a cobra booster so I didn't have to worry about the offset holes, but they are difficult to find and I do not have a core to have repaired. I can get a Duralast one, but I wanted to avoid that for a Cardone unit, which are hard to come by these days. I am not any kind of master mechanic, but I know my way around a car and tools and I could not get this thing in without clearancing the strut tower. I taped off the tower and I mark where the booster is touching and I try to precisely hit only the spots where it is catching. It seems to be working well and i'm getting there, but then I ran into this problem. I am sure that I will get it, but I would agree that this is the hardest thing to date I have tried to do on a foxbody.