Master brake and booster

Morning,

Another weekend on the kit and we're making great progress (I think...), 4 axle lugs replaced with 5 lug, removed the drum brakes, shields and went with full disc setup 11" rotors...looks great. Now we're doing firewall next and getting the emerg brake cables in, this weekend we will hang the rear diff into the 4 linkup, fuel tank, all go!

Question: In the manual it calls for installing master cylinder and proportional valve. I dug out the ones which came off the 89 mustang donor car and they seem in pretty decent shape and I think will do the job as I can't see a major difference between an 89 and a 78 mustang II.

I checked a few suppliers and they have a master cylinder and booster kit (8" and 9"booster) combo's available, pretty reasonable price. Anyone know if these bolt in with the current clearance from the firewall to give power assisted brakes? Or with the disc setup we have, would the master cylinder and proportional valve suffice?

Cheers,
Mark

In 2010, I had our "MX" converted from manual front disc brake /rear drum brakes to a power assisted setup {NAPA Cardone #54-73201}. There was some interference with the drivers side inner fender liner ... Dremel tool corrected ! Huge improvement in braking. Front brake conversion done with SSBC kit # SSA148-1A
[5 lug Ford on 4.5" centres] widened front track approx.0.5".

JimboQuick

Cheers JimboQuick, so did a quick google search for NAPA Cardone #54-73201, looks like the brake booster is something similar to what we have here. Was that easy to bolt into the firewall and run the brake pedal connector through the firewall?

Think it would stick out not to bad as the master cylinder bolts onto the front of it from what i've seen online. This is one I've been looking at as its disc/disc

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Chrome will match rest of engine we're getting done.

The proportioning valve is unlikely to work well. Mustang is front heavy and has drum brakes in the rear as well as tons of dive under braking. Your car is about 50/50 balanced and will have much more braking power in the back so probably a very different balance. You can get adjustable proportioning valves and do the old lock em up test, if the rears lock up before the fronts you send more power forward or the other way around till you get lock up at the same time front and rear.

yeah we replaced the front end with QA1 suspension front disc on 11" rotors, replaced rear drums and converted over to disc on rear as well with same 11" rotors. Looks awesome, so i think i'm going to pick up the master/booster config from Jegs and add to car.

As the firewall is only fiberrglas, seem to remember that some work had to be done to keep "firewall-flexing under braking" from becoming an issue. T'was about eight years ago when I had this work done ... but braking is not an issue in our MX. Our vacuum booster set-up is probably more than what we needed, but I was concerned about the amount of vacuum generated by the slightly modified "ZZ4" engine.

JimboQuick