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Power brake conversion questions.

1K views 9 replies 7 participants last post by  Telecomboss 
#1 ·
My 66 coupe currently has four wheel manual drum brakes with a 4 bolt 7.25 rear end. I'm looking at doing the Granada front swap for disks and going with either a Granada 8" with drums or Explorer 8.8" with disks on the rear. I currently have a C4 auto but would like to swap in a T5 in the future. My questions concern the booster and pedal. What size booster is the correct one? I assume 7" but I'm not positive. Is it necessary to replace the brake pedal or will my current one work with the power booster?
 
#2 ·
Some a/m kits are designed to reuse the stock pedal by adding a bracket to change the pivot point. There are many options for a booster- you'll just want to look for one specific to your application and disc/disc combo. Google this question and you'll be busy for the next 3 days! Although the Granada gig was popular back when, there are way to many better/newer/almost as cheap options on todays market to go with. Google that too..
 
#3 ·
gt350sr is right on.

I did the Granada swap ages ago and it's treated me well, but with all the options available now, I would probably go a different direction. I personally like the solutions that use newer Mustang parts. While you're at it, forget the Granada rear and go with the Explorer swap.

As for power brakes and T-5 swap, I can't say enough good things about the Mustang Steve parts. Roller bearing clutch, Fox Mustang 4cyl brake booster and clutch cable kit are all fantastic. If I had a C4 with distant plans for a T-5 swap, I would go ahead and do the pedal swap/upgrade and hide the clutch pedal under the carpet just so I could do the MS Fox 4cyl power brake swap while I'm at it.
 
#4 ·
My 66 coupe has a fox body 4 cyl booster, sn95 mustang master cylinder 1" bore, front 03 brakes, a, pedal support firewall bracket welded on to match the fox booster, and a pedal pin relocation.
The pin and bracket are from mustangSteve.com, as is the brake mounting hardware. You do need v8 spindles tho.
I've only driven in the neighborhood but the brakes work well. I plan to go disc in the rear once I wear out the new drums I got with the posi 8" diff I bought.
Check mustangSteve.com all you'll need is there
 
#9 ·
So sell the Granada and use to proceeds to buy parts that actually fit. Really. The Granada stuff won't kill you, but the steering geometry is wrong and cannot be made right.

By the time you get all that cheap junkyard crap cleaned up and safe to use, you could have bought a disc brake kit with all new parts.
 
#6 ·
If you can weld, or have a buddy that can, I'd consider the Explorer axle like Blake mentioned- that's what I did. You can score them pretty cheap- some have really great gears, 31 splines, posi gears, and disc brakes; great upgrades all at once for little money.
 
#8 ·
For the power booster, you will have to decide if you're ever going to be using the stock Z-bar clutch linkage because there is a difference in how the booster mounts in a '65/'66 car. The auto boosters mount flush up against the firewall, while the manual boosters have bracketry that stands them up and away from the firewall so that they can clear the stock clutch linkage. With a T5 I'd imagine you'd use a cable clutch, so you won't have to worry about clearing the stock linkage.

As long as you have no plans to put the stock clutch linkage in, then use a booster for an auto trans car - it will give you a lot more room for a dual bowl master cylinder. It can be a real bear trying to get a dual bowl and manual trans booster in between the shock tower and the firewall. IIRC both boosters are identical in diameter (7"), just different brackets.

I've also seen reports of people using Fox boosters in their cars with good success as long as a cable or hydraulic clutch is used.

Brake pedals should be the same for an auto/manual car. However, you should check to see where your brake light switch is. Some brake pedals (mine) came without a mount for the typical spring-loaded brake light switch, as the brake light switch was instead pressure-operated and located on the master cylinder. If you swap to a master cylinder that has no provision for such a switch, and have a pedal that doesn't let you put the spring-loaded switch, you'll be cussing up a storm.
 
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