Need Info on Manual Brake Swap

[Rcdgl]

So while I have the brake booster out for rust removal, I am going to swap to manual brakes.

Looked at a bunch of kits. I have the stock 80 ish manual brake adapter for the firewall that will accept the original master with just new lines and some adapting of the pushrod.

However, what experience have some of you had with a different pedal to get the ratio right, and what is a good master to put in.

I have stock 82 Mustang straight six brakes......

 

[AeroCoupe]

So 10” front discs and 7.5 axle drums?

 

[Rcdgl]

Yep, stock 82 six banger brakes, including a 7.5 in rear. I have some 8.8s but have not needed one yet. Best is 7.50 in the eighth.

 

[AeroCoupe]

Big thread on this here:

https://www.yellowbullet.com/threads/fox-body-manual-brake-conversion.556652/page-7

 

[revhead347]

Yep, stock 82 six banger brakes, including a 7.5 in rear. I have some 8.8s but have not needed one yet. Best is 7.50 in the eighth.

Manual brake conversions are generally used with specific brake kits. I don't think it will work with stock brakes. I tried it once, and immediately upgraded the brakes.

Kurt

 

[Rcdgl]

Plan a is to get the pedal, pushrod and bracket kit, and start with the old mc.

If that doesnt work, I will go to a different mc.

 

[Mustang5L5]

Did 1982 come with manual brakes? If so, I’d start for track down those parts to use. Gonna take a little digging

 

[AeroCoupe]

79-82 Mustangs were offered with manual brakes. Key is to run a master cylinder with a piston diameter of 15/16" or less. 79-86 Mustangs have SAE threads on the MC where 87 and up are metric. According to Maximum Motorsports all Ford Mustang metric brake fittings are ISO bubble flare and all of the standard flare (double since it is a brake system) are English SAE.

One of my friends has a 69 FB with manual brakes with all stock parts and it stops really good. It has the Granada front discs and the big nine inch drums with a stock MC with a 15/16" piston (we just replaced it which is why I know) and has all kinds of pedal to slow the 408 stroker down.

 

[General karthief]

I believe there is a difference between the power brake master cylinder and the manual master cylinder or the peddle ratio or both, do the research, if you get it wrong the peddle effort will be effected.
My question is why swap to non-power brake system?

 

[AeroCoupe]

Pedal ratio and how to move the pin on the pedal is discussed in the link I have in Post #4. Believe Jack Hidley from Maximum Motorsports chimes in and has some good info on that.

 

[Mustang5L5]

I think Jack retired or moved on.... He's been MIA from forums and social media for a while. On a recent tech question to MM, someone else answered. Jack has always historically answered my questions.


From what i am aware of, the early Mustangs with Manual brakes used a 7/8" bore MC. 1982 seems to also have a 21mm manual brake MC. I don't know specifics of what goes where, only going by Rockauto listings which aren't always correct.

Pedal ratio is different as well, but I believe the MM kits are designed specifically for non-manual Masters.

Really there is two ways to go about this. Buy the correct 79-82 manual brake pedal box and MC, or purchase the MM manual brake conversion kit and recommended master.

Manual Brake Conversion Kit, 1979-1993 Mustang

I can't recommend the proper MC here. WOuld need to pay the $30 for MM to tell you which one to use under their tech services page. Then you'll need to toss on the MC and brake line fittings.

So $300 or so?

 

[AeroCoupe]

Or you can buy a $75 to $100 MC and just relocate the pin on the existing brake pedal. 7/8" bore is the common choice in an MC for manual brakes on a stock Fox Mustang brake setup.

Probably the most commonly used for SAE brake fittings is the 83-85 Ford Ranger for manual brakes. Another one that is used is the M1931 from either Napa or AutoZone if you can find it.

Pedal ratio is easily figured out. Just measure the distance between the center of the pivot (of the brake pedal), to the center of the pedal and record. Next, measure the distance from the center of the pivot to the center of the pin or bolt used to connect the MC push rod to the brake pedal and record. Divide the larger number by the smaller number and there is the ratio. For manual brakes, you're looking for a min of 6:1 and most say 6.5:1 or 7:1 if you can get it. The other thing is the MC rod need to stay parallel to the MC so that when it is being pushed into the MC is does not bind the piston.

 

[Rcdgl]

Ordered the Maximum Motorsports pedal and bracket kit from LMR today.

 

[AeroCoupe]

If you want one of the newer style MC’s looks like a 1986 Bronco II will work but the ports are a different thread.

1986 Bronco II MC:
Port 1 Thread Size (Forward) (in): 9/16-18 Inch
Port 2 Thread Size (in): 7/16-24 Inch

Possible direct bolt in and fairly economical is a 1975 Granada MC:

Port 1 Thread Size (Forward) (in): 3/8-24 Inch
Port 2 Thread Size (in): 7/16-24 Inch

 

[Noobz347]

Granada


That's all I got.