Brakes

[MarlboroMan73coupe]

I have my 73 mustang I’m working on. It’s up on the lift and I’m at the point of deciding wether or not to convert to rear disc brakes. I was looking for second opinions as to wether it is advised

 

[71ProjectJunk]

This is more of a do you want the car to brake a little better, than is it advised kind of question. The rear drums work fine for normal driving, and even some spirited driving, but obviously drums have their limitations. If all you do is drive the car occasionally on the weekends to a car show, or a pleasure cruise, I see no reason to ditch the drums, but if you occasionally race the car, the rear discs will definitely be a noticeable improvement, plus they look cool with modern wheels

 

[tony-muscle]

This is more of a do you want the car to brake a little better, than is it advised kind of question. The rear drums work fine for normal driving, and even some spirited driving, but obviously drums have their limitations. If all you do is drive the car occasionally on the weekends to a car show, or a pleasure cruise, I see no reason to ditch the drums, but if you occasionally race the car, the rear discs will definitely be a noticeable improvement, plus they look cool with modern wheels

+1 Agree

 

[MarlboroMan73coupe]

This is more of a do you want the car to brake a little better, than is it advised kind of question. The rear drums work fine for normal driving, and even some spirited driving, but obviously drums have their limitations. If all you do is drive the car occasionally on the weekends to a car show, or a pleasure cruise, I see no reason to ditch the drums, but if you occasionally race the car, the rear discs will definitely be a noticeable improvement, plus they look cool with modern wheels

That’s my plan is for more aggressive driving and taking it to the track but also driving it to and from work etc

 

[71ProjectJunk]

This all will boil down to your budget, if your budget allows for a rear disc brake conversion, I see no reason why you should not do it. The only question, if you have a limited budget, is if those funds could be better used somewhere else.

 

[Don C]

The cheapest and easiest way to upgrade the rear drums is to put on the Fairlane station wagon rear drums:

How-To: Shelby Rear Brake Trick on Early Mustangs (motortrend.com)

You can get new ones from NPD

DRUM, BRAKE, REAR - #1126-4 - National Parts Depot (npdlink.com)

These will give you about a 25% increase in braking surface area, plus the added cooling, and they'll look a little better than the plain drums.

 

[Hemikiller]

Most cost effective upgrade you can make is better friction materials. Hawk, Porterfield & EBC make pads and shoes that fit our cars.

 

[mrgmhale]

This is more of a do you want the car to brake a little better, than is it advised kind of question. The rear drums work fine for normal driving, and even some spirited driving, but obviously drums have their limitations. If all you do is drive the car occasionally on the weekends to a car show, or a pleasure cruise, I see no reason to ditch the drums, but if you occasionally race the car, the rear discs will definitely be a noticeable improvement, plus they look cool with modern wheels

I agree re: if using it for street driving, leave the drum brakes in place - they are fine. If you are racing get all disc. But, if you do go 4 wheel disc be sure to remove the Residual Pressure Check Valve from the master cylinder's rear fluid outlet port (under the brass seat), otherwise you will have rear dic brakes that will always have some pressure applied to them. That would result in overheated rear brake pads/rotor, rear brakes wearing quickly, and reduced performance.

 

[PoFoMoCo]

The cheapest and easiest way to upgrade the rear drums is to put on the Fairlane station wagon rear drums:

How-To: Shelby Rear Brake Trick on Early Mustangs (motortrend.com)

You can get new ones from NPD

DRUM, BRAKE, REAR - #1126-4 - National Parts Depot (npdlink.com)

These will give you about a 25% increase in braking surface area, plus the added cooling, and they'll look a little better than the plain drums.

Most cost effective upgrade you can make is better friction materials. Hawk, Porterfield & EBC make pads and shoes that fit our cars.

Gents - Thanks for the information. I want to do this with my Shelby Europa build. I don't need to do a drum - disc conversion, the expense is not justified for my weekender. But I love adding more performance to the rear brakes. Also, in your experiences... what are the best shoe options for this drum upgrade?

I will do the research to make sure this upgrade works for my car. In the end, an upgrade to better friction material may be best.

 

[Don C]

Centric, for both function and quality.

 

[bucketlist fastback]

The cheapest and easiest way to upgrade the rear drums is to put on the Fairlane station wagon rear drums:

How-To: Shelby Rear Brake Trick on Early Mustangs (motortrend.com)

You can get new ones from NPD

DRUM, BRAKE, REAR - #1126-4 - National Parts Depot (npdlink.com)

These will give you about a 25% increase in braking surface area, plus the added cooling, and they'll look a little better than the plain drums.

Don, I have been looking for a little clarification on the “Fairlane rear drum conversion“. Wouldn’t you have to change backing plates? I somehow assumed if you changed to wider brake shoes the geometry to the wheel cylinder and bottom pin would be different and not line up precisely?

 

[Hemikiller]

Don, I have been looking for a little clarification on the “Fairlane rear drum conversion“. Wouldn’t you have to change backing plates? I somehow assumed if you changed to wider brake shoes the geometry to the wheel cylinder and bottom pin would be different and not line up precisely?

The drums Don linked to are the same depth from axle flange to the backing plate. The extra surface area is out towards the wheel. I marked up the pic from the article. You will need the longer anchor pins for the 2 1/2" rear shoes. A manual brake proportioning valve may also be required, as the extra stopping force may overpower the rear tires.

 

[351c1971]

If I remember correctly, when Shelby did this modification, he added a separate manual brake proportioning valve under the back seat.

 

[Paul M]

I have a 73 with a factory high performance suspension package and the rear drums are the larger (over 2"shoes). If you find a later 72-3 Mach with the staggered shocks and rear sway bar it will have them. My problem was most master cylinders sold in the local stores didn't work, they are something like .940 diam and I needed a full 1" piston master cylinder to make it function.

 

[mrgmhale]

Gents - Thanks for the information. I want to do this with my Shelby Europa build. I don't need to do a drum - disc conversion, the expense is not justified for my weekender. But I love adding more performance to the rear brakes. Also, in your experiences... what are the best shoe options for this drum upgrade?

I will do the research to make sure this upgrade works for my car. In the end, an upgrade to better friction material may be best.

If this is a Shelby Europa tribute, and you really want to crank up the rear brake performance, you have two options that would provide effective results. One is to upgrade the rear drum brake system as noted above (Falcon station wagon brake parts). The other is to do the rear disc conversion, while paying heed to my aforementioned Residual Pressure Check Valve being removed from the Master Cylinder rear brake outlet port as it is neither needed or wanted with a disc brake solution. Better yet, get a Master Cylinder that is designed for front and rear disc brake systems, as the bore size and perhaps reservoir capacity, will likely not be the same as for rear drum brakes.

Frankly, because the majority of braking is handled by the front brakes, a rear disc brake system is overkill unless you are really going to push the car to the max, where the rear drums and linings are truly running too hot and you begin to suffer brake fade. Frankly, unless you are going to be running a very powerful, beefed up engine with the appropriately matched power train, rear disc brakes are going to be overkill. You would be better off putting the money into high quality performance oriented tires. Regardless, if you end up modifying the rear brakes be certain to document the process thoroughly so years from now you know what parts to purchase if/when necessary (rubber hydraulic hoses, wheel cylinders, brake shoes and lining, drum brake return springs and adjuster cabling/hardware OR caliper, pads/lining.

That said, if you have a "real" Shelby Europa I sincerely suggest you leave it in factory stock configuration. Even if you never plan to sell it, perhaps an heir down the road may want or need to. If I were looking to purchase another vintage Shelby (we have a 1969 GT500 already) I would not purchase one that has been modified, especially for the price a pure stock one would command. There really is no need to do anything big on the rear brakes. They are plenty beefy as it is. IMHO.

If it sounds like I am being a bit opinionated, perhaps I am. The vehicle is not mine, so I have no real say in the matter. But, you were asking for opinions. Take mine for what it is worth. I will not be offended if you do something I suggested you avoid making needless changes. But, a change to the braking system is more than just a notion. I would consider the ramifications of ending up with a vehicle that "over-brakes" in the rear. Trying to get a good balance could become tricky. Especially on a track car. FWIW...

 

[PoFoMoCo]

Thanks GM, your input and opinion are appreciated.