Cobra Brake Install on Foxbody

[02greyGT]

I used it quite a bit (strut bolts, ball joint to spindle, tie rod to spindle, lugs, etc.) It's pretty darn handy and I picked it up on sale for $49!

Yeah, I got one of the 20% coupons as well. I am a cheap bastard.

[46Tbird]

I think I may have mentioned getting the '94-95 spindles, lol.

So I have a question. Your bleeder valves on the front calipers - are they positioned at the top of the caliper, pointing up? Or are they lower down, and horizontal?

They should be pointing up. That way they can evacuate all the air in the front brake system when you bleed them. If they are pointing out, air gets trapped in the system above them and you can't bleed that out. If that's the case, you need to swap the calipers side-to-side and bleed the front brakes again.

[Doug Hatton]

They're up... I made sure of that before installing.... touche' on the spindles...

[Doug Hatton]

Just ordered a '94/'95 MC, booster, proportioning valve, 3-2 kit and delete kit. I love spending money... :\ BUT, at least it'll be right and will require very little investment once I decide to do discs in the back down the road.

[jw33]

The MM stuff will come with directions and they are actually really good. And yes when/if you go with rear disc all you have to do is play with the proportioning valve to get the bite you want. Bench bleeding is easy. If it's a parts store master it should come with two plastic threaded nipples that go into both ports on the side. Clamp the master into a vise, screw the plastic fittings both in, put a 8-10 inch long peice of hose on each nipple, route the other open end of the hose into the fluid tank on top of the master, fill the tank with your fluid, and then cycle the piston slowly a few times until no air appears to be getting pushed out.

Did you get the rod that goes in between the master/booster? Also the holes for the booster where it mounts to the body wont line up. You'll have to reem a couple of them out pretty good, but you'll never see it once it goes back together.

[Doug Hatton]

I read up on installing the '94/'95 booster. Sounds like you have to maybe drill a new hole and elongate a couple others. PM Sent.....

[TX21]

So you can't use the Cobra calipers with the stock fox booster or MC?

[Doug Hatton]

Well, you'll probably get differing opinions on what will work and what won't, but in short, I've come to the conclusion that no, you can't. I think the stock mc just doesn't push enough fluid. The stock MC has an internal bore of 21mm which is about 7/8" whereas the '94/'95 mc has a 1-1/16" bore. So, you change the MC to move more fluid, but then it doesn't apply as much pressure (volume vs. pressure) so you need the bigger booster. I've read 50+ threads on Corral over the last few days and there's case after case of people trying to make things work and most of them end up doing what I'm doing.

[TX21]

Well, you'll probably get differing opinions on what will work and what won't, but in short, I've come to the conclusion that no, you can't. I think the stock mc just doesn't push enough fluid. The stock MC has an internal bore of 21mm which is about 7/8" whereas the '94/'95 mc has a 1-1/16" bore. So, you change the MC to move more fluid, but then it doesn't apply as much pressure (volume vs. pressure) so you need the bigger booster. I've read 50+ threads on Corral over the last few days and there's case after case of people trying to make things work and most of them end up doing what I'm doing.

Dam I don't really dont want to change my booster/mc. but those calipers look killer!

[jw33]

A lot of things will work, but Like Doug said in order to work the best you need to match the right parts together.

[garycrist]

The trick to mounting the big boosters in Foxes is grinding out the 2 holes toward the center line of the car. The firewall is 2 pieces separated by a 1/2 inch thick piece of plastic. All I did was Dremel out the two inside holes about 1/2-3/4 inch under the hood.
Also hog out the plastic between the firewall halves. The trick is to get the booster to roll in...

[turbos66coupe]

Ford racing sells an adapter plug to modify the stock pv . They say its neccesary to get more fluid to the bigger brakes up front.

[Doug Hatton]

I'm guessing you're talking about this?

http://www.latemodelrestoration.com/item/M2450A/Mustang-Brake-Proportioning-Valve-Plug

I'm not really sure what that does, but I don't have rear discs....

[noslow5_0]

Doug,

I installed the same spindles/hubs as you on my fox. I ended up installing a set of 05-up bullits as the offset is a different. If IIRC 94-04 is 30mm and 05-up is 45mm on a factory wheel. The more positive offset the more it will pull the wheel back into the fender. My bullits sit in the same place as the 4 lug ponys did. Just food for thought before you rip the front end all apart to swap spindles.

[Doug Hatton]

Cool. It doesn't look horrible right now with the Saleens, but I'm mostly concerned about running my skinnies at the track. I have a spacer I'll have to use to clear the Cobra calipers and that will push them out even more, to the point that I don't think they'll work. For now, on the street tires, it's ok, not perfect, but ok. I'm more concerned with getting the braking issues sorted out first. Thx.