I will be starting a general overhaul of the major systems this spring on my early production 1964 1/2 Mustang and I am considering the pros and cons of changing the front drum brakes to disc. I appreciate the safety upgrade to disc but will this type of change devalue the car? The car is very close to original ( still has a generator for example) and I prefer to keep it as close to stock as feasible. The car is not used heavily putting on less than 1000 miles a year generally on weekends on low traffic and close to home. What do you all think about this issue ?
I’d say go for it, after all you don’t want to do all that work and then wrap it around a tree because you couldn’t get it stopped! In terms of value, as long as you don’t do anything that can’t easily be undone, the value won’t go down and for some buyers it will actually go up! Just hang on to all the original parts so can pass them along to the next owner if you ever do decide to sell.
Disc brakes are a great upgrade and I highly encourage it. You aren’t going to harm the value either. Unless your car is super rare or desirable (like an early K-code) I wouldn’t worry about it there are still plenty of early mustangs out there. Like @spsmailbox said, don’t do a conversion you can’t undo. Keep the components you remove as well. One word of caution though, if your lines have never been disturbed, I would prepare yourself for the possibility of needing to just redo the lines. I ran into that problem last winter on my 69 Pontiac when replacing the hoses. Next thing I know and I’m buying a pre-bent stainless steel line kit from Inline Tube because I snapped a nut off.
I don’t know, unless those 1000 miles are in the mountains or at track events, why? Drum brakes were around a LONG time and for relaxed cruising there’s nothing inherently unsafe or a significant performance gain to be had by going disc. All else being equal (tires, suspension, weight, speed etc.) stopping distance won’t change on a panic (locked) stop. And either way, at that little mileage, you’ll probably be changing shoes or pads before they’re out of material.
If I were overhauling systems, I’d pay attention to the master cylinder, wheel cylinders and lines for safety before considering discs. My .02.
Disk brakes are great, don’t mistake the second half of this post for talking down on disk brakes.
That said, leave it with drum brakes. A well assembled and adjusted set of drum brakes is plenty of braking power for cars in modern traffic. Also, even the best conversion kit is still a conversion kit and requires a certain amount of pain in the butt to complete. If the part are available to rebuild the drum system that is already on the car, it will serve you well for many years. Also, you mention you want to keep it stock. no reason to store a bunch of parts to return the car to stock in the future when you can keep it stock now.
I disagree with both Jim-R and Kyle on this. While it is true that stopping distance in a lock up situation is all about the tires, the point is not to lock up your brakes in the first place, even in a panic stop as this will considerably lengthen your stopping distance over a controlled stop. Under a controlled stop at impending lock up disc brakes will shorten your stopping distance even on the first stop and the gains will only increase after multiple stops. Also, disc brakes are easier to modulate than drums making it easier to keep from locking up the brakes. I also disagree that drum bakes have plenty of power to stop your car in modern traffic. If your are rolling down the highway at 60 mph and the 2019 Mustang in front of you slams on his or her brakes those drums on your '65 Mustang wont keep you from rear ending them!
If you only plan to take your car to shows to have it judged then by all means keep it 100% stock but if your plan is to drive it, it only makes sense to do some upgrades that will improve the safety, reliability and driving experience. Things such as, modern radial tires, disc brakes, electronic ignition, modern charging system and upgraded steering and suspension parts. All of these are things that can easily be undone if you so chose to. I also believe that you should drive and enjoy your car until you or it dies and let someone else worry about its value.
If a 2019 Mustang slams on their brakes in front of the OP, it’s going to depend on the distance the OP was following, not whether he had disc or drums. And ONLY the most disciplined driver is going to stab brakes on a panic stop. 99 out of 100 are going to lock them. And then it’s also function of tire (size, compound, construction), suspension, a vehicle’s weight and it’s distribution). As Kyle stated, I’m not bagging on discs. And thinking about it there is no right or wrong answer b/c discs certainly won’t HURT anything. But for the OP’s usage of the car putting front discs on is spending significant money and effort to fix something that isn’t broken.
Since he is going to overhaul the major systems of the car anyway adding disc brakes will not significantly increase the cost of that rebuild. If you are locking up your brakes in a panic situation it’s time to take a driving course, remember that the 99% have antilock brakes! The distance he was following the 2019 by can be reduced by having disc brakes, and in modern traffic if you leave more than 3" between you and the car in front of you 6 cars will try and cut in!
In my experience, on a car with no ABS almost EVERYONE will lock up even the front wheels with enough speed. As a former police EVO instructor we had an old Crown Vic that we could disable the ABS on. The only guy that I recall NOT locking them up on unrehearsed training was someone who tracked a car regularly. Discs, IMO, will not significantly change stopping distance in a panic stop of a non-ABS equipped car…all else being equal. To simply assume so is to buy everything those guys on those program-length car shows I watch on weekend mornings have to sell.
Again, it’s not going to hurt anything. But the expense (guessing around $1k) and effort is not worth it IMO for the way the OP uses the car. Replacing any old flex-line, hard line, rebuilding master and wheel cylinders and flushing the system for sure.
Front disc brake kits for a 65 Mustang run in the $600-700 range. If you pull out the cost of rebuilding the drum brakes the cost difference is $300-400. In his statement he said he was planning an overhaul of the major systems of the car, which would include the brake system. I for one don’t consider a safety upgrade to the most important system of a car to be not worth the cost or effort. Disc brakes improve brake performance and shorten stopping distance. To say that they don’t is not supporting by brake tests. You are right that in a lock up situation braking distance is determined by tire grip, but most stops are not in a lock up situation, so in most instances disc brakes work better! I restore classic cars for a living so I know the improvement that disc brakes offer first hand and I will tell you that the first upgrade I make to any of my own cars that came with drum brake is to replace them with discs just as I did on my 66 El Camino. I also swapped the single master for a dual master, again as a safety upgrade.