Braking Options

72MachSpeed

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I am in the process of putting on new brakes on my 72. The factory option already has disc brakes in the front and the typical drums in the back. For me this is a new world when it comes to either finding a direct replacement for the stock setup Vs. upgrading and getting a better set of brakes all the way around. What are your opinions? What have you guys done to your braking systems on your cars? If you have gone disc brakes all the way around what brand did you go with?

Sorry for all the questions but the braking side of vehicles isn't my forte! haha

Thank you all for the help along the way.

 

Lazarus

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I have a 73 with stock power disc setup (disc front/rear drum).  On my 72 I had the same, but wanted discs all around so I had a popular conversion done on the back (search on the “Explorer rear disc conversion”).  The rear discs function well, were not very expensive, and look nice through my rims... but they don’t really make a massive difference in performance over my 73 to be honest. 
 

As muscle cars I have experience with go, the stock power disc/drum setup on ours is actually pretty good. A big step up from my 67 Camaro’s 4 wheel manual drums I can tell you that!
 

If I were to do the 72 again, I’d consider skipping the rear conversion.  It just didn’t make a huge difference for me, given that most of the braking comes from the front.  I personally have not driven one of our models with a more modern, high-performance setup all around, so I can’t speak to the gains on those. My experience is just comparing the impact of changing just the rear drums, for what it is worth. 
 

 

mjlan

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I've never had any issues with the OE power-assisted disc/ drum setup.

What issues are you experiencing? Sometimes incorrect parts have been installed and they create problems.

The biggest contributor to the overall braking performance of a car is the tires. Make sure they are good quality, not old and hard and inflated properly.

Sounds lame but true!

 

Don C

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A big issue with older vehicles is rotors and drums out of wear limits. The other related problem is people installing new pads and shoes without having the rotors and drums turned (machined) for a true and proper surface for the new pads and shoes to break into. Sometimes this is done deliberately because having them turned will cause them to exceed the wear limits of the rotors or drums, other times just a quick and dirty brake job by an owner that doesn't know better or an unscrupulous shop. 

Good quality pads and shoes and rotors and drums in good condition will provide you with more than adequate brakes. The stock disc/drum brakes in mine function very well, even on windy downhill mountain roads where they get a workout. I've thought about rear discs, more for the cool factor than need, but have other places to better spend my Mustang funds.

 
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Hemikiller

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A solid rebuild on the stock disc/drum system will work extremely well. All new/rebuilt parts with a few key upgrades such as stainless braided flex hoses and semi-metallic friction materials does wonders. 

 

Fabrice

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 but have other places to better spend my Mustang funds.
And which other places could be better than spending mustang funds on the mustang?? :D
Btw any picts of your horse on here?

 

Fabrice

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All new/rebuilt parts with a few key upgrades such as stainless braided flex hoses and semi-metallic friction materials does wonders. 
+1. They work very well and do not feel 50 years old at all.
Oh and while at it, I have bought the Stainless classic tube kit from CJP a while back for my 71. As I need/want to change all the lines.
You can see it's quality on first sight, nice labeling to quickly know where all goes, good fittings with their threads nicely treated. For $50 I really don't see the need to spend hours making lines or even doubt if changing old rusty lines could wait. I don't know why they are so affordable btw. I recall replace the rear end line with the same brand 20 years ago on my 73 and only that bit was twice the price of this kit for the entire car.

 
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Don C

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I meant better things to spend them on the Mustang, like the engine, which I should be able to start on in a couple of months. Right now the engine bay is empty, the interior is completely stripped, needs new weather stripping around the windows, including rear window, and it's been languishing in a storage shed for 9 months. Should have the new workshop ready for it to move into next month. Here's a picture of it from when we lived in Las Vegas before I could get it under cover, which is why it needs new weather stripping, the 115°F (46°C) sunshine wiped it out.

Right & front.JPG

 

72MachSpeed

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That is what I like to hear my goal is to just swap the stock to new pads and just give it an update.  Right now what is wrong with it is that the brakes are super soft as I need to really step on it to stop in reverse or driving normally.  I really think that it just needs a new set put on it. What brand did you guys go with for the fronts ? Honestly with mine I think it'd the original set as it only has 36k on it .

 
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knn

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I've found that if you're looking for a cruiser (i.e. not road racing, autocross, etc.), the stock front disk/rear drum setup works just fine for the weight of the car.  As was pointed out above, most of the braking is done up front so changing to rear disc (albeit a fun project) isn't going to make that much difference, at least not in dry conditions.  

What struck me was, "super soft as I need to really step on it to stop in reverse".  You didn't say you hear grinding when your brake so I don't think just freshening up the pads/shoes will solve this.  Assuming everything else is working, it sounds to me like the brake system needs to be bled and the rear shoes adjusted.

Here's what I did on our Mach 1 when she had similar problems:

  • Checked all four corners to make sure we weren't metal-to-metal
  • Checked to make sure all four corners were actually working (had one sticking caliper and one leaky wheel cylinder)
  • Flushed and bled the hydraulic system
  • Hand adjusted the rear brakes

If the above doesn't fix your problem, it could be the master cylinder.  Luckily most of these parts are inexpensive ($25 for calipers, $15 for wheel cylinders), but stick with a good brand when replacing parts.  I've had good luck with Raybestos.

BTW, once everything is in working order, the rear self-adjusters work when you hit the brakes in reverse.  I had a '67 once that almost only ever saw forward driving.  The brakes never felt right until I figured out the self-adjusters.  After that, I made sure to get some solid reverse braking in every week.  Problem solved.

Good luck,

Nick

 

droptop73

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Another thing to check if the pedal is spongy are the flex hoses. 

 

72MachSpeed

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Thanks for the help KNN! I will take a look and see what I find out. 

 
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c9zx

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Perhaps the booster push rod is not adjusted to the proper length (too short). Just a thought. Chuck

 

Spike Morelli

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One might consider larger rear drum brakes,  as opposed to the disc swap, like Shelby American did on their GT-350 race cars. Shelby American also went with sintered metallic linings to resist fade. Larger rear drum brakes make some sense to me, as I've always known that there is more frictional area with drums over discs, and as an example, semi-trucks have utilized drums on their tractors and trailers for so many years, and they really have to stop some weight and big rolling stock.   I'm sure that discs are the best way to go always, in the front, but possibly there is a van or station wagon rear larger drum swap-in that would work well in the rear on our 71-73 vehicles.

 

knn

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One might consider larger rear drum brakes,  as opposed to the disc swap, like Shelby American did on their GT-350 race cars. Shelby American also went with sintered metallic linings to resist fade. Larger rear drum brakes make some sense to me, as I've always known that there is more frictional area with drums over discs, and as an example, semi-trucks have utilized drums on their tractors and trailers for so many years, and they really have to stop some weight and big rolling stock.   I'm sure that discs are the best way to go always, in the front, but possibly there is a van or station wagon rear larger drum swap-in that would work well in the rear on our 71-73 vehicles.
@Spike Morelli the only problem I have with drum brakes is when they get wet.  We had an old IHC Travelall when I was a kid.  Whenever it would rain and we hit a puddle, water would get into the drums and make it impossible to stop for a light.  

 

droptop73

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The other issue with drum brakes is a tendency to self energize which locks the rear brakes until the braking load is gone. If you ever had it happen you won't forget it! LOL

 
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I am old enough to remember when I helped my dad do brake jobs about 60 years ago. You went to parts store and they sold you just the lining without the metal shoe. You got a little box of rivets and a hand held rivet forming tool. I would hold the shoes on a metal plate and dad would roll the rivets over. Then they went to bonding the linings on.
You do not find them very often anymore but there is a special machine to grind the matching arch on the shoe that the diameter of the drum is. When you turn the drum you depart from the nominal so when the shoe goes out it only hits on a small area until it wears in to fit the diameter of the drum.
I never had issue with drum brakes on my old 1950 you had to adjust your brakes were not self adjusting. Me and dad would go for test drive and he would stand on the brakes. We would adjust each one until when you hit the brakes all 4 tires would slide and you could let go of the steering wheel and car would go straight.
Some may not realize when you put new rear shoes on you need to have the shoes ground to the same as drum. Then when you get it all back together you need to be backing up at a good clip and hit the brakes hard several time. The adjusters only work going in reverse to self adjust.
Spike was talking about going with bigger drums. When I worked in the racing shop the owner had all the local junk yards give him a call when I think it was Buicks came in. A few years had huge aluminum brake drums with an iron liner for the braking. We put them on every chassis we built.
If you go back to some of the specs on cars ones with 4 wheel drum got about one more mile to the gallon on gas. Disc brakes do not retract from the rotor so there is drag there always.
One thing I learned watching Kenny Brown's cars and coffee and he also has seminars on building track cars. If you do not know who he is he won the Trans Am championship 8 times and has built over 200 track cars for racers. So he knows a little about brakes.
The question came up once about using the Explorer disc brake rear in a track car to get the disc in rear. He said that did not work for a race car. Rears with clipped in axles have end play and will move in and out quite a bit you hear them go clunk as they shift. My SVO and 20 anniversary both do. He said each time you go into a turn the axle and disc shift pushing the piston in the caliper back. So when you brake next you have to pump the pedal which on a race car is not good. He stated the 9" Lincoln, Granada and Monarch was a much better choice for a track days car since axles are bolted in and do not shift but also has disc brakes.
He also point out that the new IRS on the Mustang is causing the rear ends to go out really quick on a race car. With the gears in the center section and the IRS not being solid there was not enough mass to pull the heat out of the rear even with the typical rear end coolers. They had to go much bigger. The housing on a solid rear draws heat from the gears and the air cools it much better. They have to do lots of changes to track cars including the Shelby cars or they will not make a full race without failing. Their brake pads are 1" thick and have several types for different tracks, they also use much larger disc and also thicker. Lots of good info and you can send in questions he does every Saturday I think 10:00 am eastern. I get email notifications.

 
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