Things to Keep In Mind as You Overhaul Your Classic Car Brakes
Going into the New Year, I thought it would be a good idea to go over brakes. This subject is one of the most important aspects of dealing with classic car restoration.
This is not necessarily a how-to piece, but more like an overall view of what to keep in mind when venturing into the DIY world of brake upgrades.
A Tale of Braking Gone Bad
A few hundred years ago I was cruising down a winding road in Mission Hills, I had the AM radio blasting in my 1966 Ford Galaxie.
I took several turns that I haphazardly did not calculate speed, sharpness, or grade – and in turn, did not see the 1985 Pontiac Ferrero rapidly approaching on the left.
By the time I hit the brakes and correct my position, I had already taken out a 2-foot-long gash on the side. Needless to say, this all could have been avoided with a few upgrades on my part.
In 1967, Federal Motor Vehicle Safety Standard 105 set specific performance tests, which led to the widespread introduction of disc brakes on American cars in the early seventies.
Before then the single port “honey jar” or death pot as I like the call it (due to the fact that if any part i.e. hard lines, soft lines, wheel cylinders or master cylinder were compromised the whole system would fail), several car lengths need to be taken into consideration when driving an all-wheel drum car.
Before You Convert Your Brakes
Before we dive into the brake conversions there are some major key elements you want to keep in mind when converting your brakes.
The first and most important is determine if you are going to use your stock wheels. Most 50s, 60s, 70s, vehicles have 14 inch or 15-inch rims that will limit the size of rotors and calipers you use to convert your front drum brakes to disc.
The second thing to take into consideration is the Prop valve or proportioning valve. This will allow full flow of brake fluid to your front disc brakes, and constricting the flow to the rear drums.
Without the prop valve, your rear drums will have a tendency to lock up on you when you brake hard, thus causing the rear end to fishtail. The third thing to keep in mind is if you are going to use a brake booster.
You will need at least 18 psi of vacuum coming off the engine intake manifold in order for the booster to work properly.
If you are running a performance cam you will need to go with an electrical vacuum assist and canister, in order to get the vacuum you need to make the brakes work effectively.
The fourth is choosing a conversion kit that is right for your budget. There are literally dozens of kits out there ranging from moderately expensive to extremely expensive.
You want to keep in mind that you want to go with a company that will have your parts readily available to you down the line; especially when you are replacing pads, rotors, etc.
I found one company that makes the kits that will allow you to use modern vehicle parts to complete your conversion – the company is called Scarebird.
Here is an excerpt of the set up for 49-53 Ford’s.
Convert your classic 1949-53 Ford to front disc brake with these brackets (made in the USA). They are AutoCAD designed and CNC laser cut for excellent tolerance.
These brackets use common and inexpensive rotors (1970-73 Mustang front, 11-1/4″) and calipers/pads (1988-91 Chevrolet or GMC 1500 work truck) available from your nearest NAPA, O’Reilly’s, Autozone, etc. or even your local boneyard.
Unlike other designs, this setup will allow you to retain your stock drum 15″ rims as shown by the picture below.
Also note that the brackets are machined to allow the use of the original attachment hardware and by doing so retains your Ford’s alignment setting.
The Mustang rotor also has the same pilot diameter (2.43″) as your OEM rims – making your rims properly centered by the hub, not the lugs. Offset is within 1/8″, preserving your original stance.
This is what I love about these guys is the use of modern components which are readily available at your local parts store, plus the price is very reasonable compared to other disc brake conversions.
There are 3 most common upgrades that will work well on your classic vehicle. I will give examples for each conversion.
1. Convert the single port master cylinder to a dual port master cylinder, then adding a brake booster to your all drum set up.
A few years ago, I had the opportunity to work on a 1964 Oldsmobile Dynamic 88. This was an all-wheel drum set up with a “death Jar” single port master cylinder with no power brake set up.
Now this car looks very similar to the Impala of that year, and I thought this is going to be a piece of cake. I will find an Impala brake conversion which will allow me to keep the stock wheels.
Well to my horror after purchasing the kit, I was attempting to mock up the rotors and calipers to the spindle. I found that they were very different, and I was devastated.
After several go-arounds, I contacted the owner who was disappointed to hear that there was no kit out there that would work with the stock wheel set up.
That day I went home determined to find some way I could improve the Olds’ braking power. After several days of research, I had finally came up with a plan.
If I could not alter the brakes themselves, I could change out the master cylinder (with which I did purchased a 1966 Cadillac dual master cylinder with brake booster, which was literally a bolt in application).
This would separate the front wheel lines from the rear wheels, thus giving added safety in case one or the other failed.
I did have to run two new lines to the front wheels, but wow! What a difference with the brake assist, it came out better than I had expected.
2. Convert the single port master cylinder to a dual port set up swapping out the front brake drums to disc brake set up.
Several months ago, I did this disc brake conversion on a 1965 Mustang. This kit is different in the aspects that the car has a manual transmission.
The owner wanted to keep the stock steel wheels, but did not want to cut up the support beam in order to fit a dual master cylinder with a brake booster.
Luckily I found the perfect kit, and using a modern plastic brake reservoir for the master cylinder; routing it to a later model of a Mustang proportioning valve.
3. Convert the single port master cylinder to a dual port set up swapping out front and rear wheel drum set up with disc brakes.
This last conversion I did on a 66 Chevy C10 a few months back. Spare no expense, the owner wanted to go with drop spindles the whole nine yards.
I knew immediately Wilwood was the brand to use. This is a high-performance Truck we needed the very best to slow down the Ls1.
I have had nothing but great experiences with this company over the years, the only drawback is they can be quite expensive.
In conclusion, it’s up to how much you want to spend. These are some of many examples you can use as a reference. In the end you will be relaxed and confident that your classic will stop on a dime!