rev up your engines, today I'm gonna talk about drum brakes on your car versus
this brakes on your car, now the back brakes on this car are drum brakes but
the front brakes they're disc brakes, hey why is it that way how did that come to
be, well drum brakes have been around for a long time hey wagons, some of them have
drawn type brakes on them, they work quite well and they've been around for a really
long time, drum brakes are exactly what they say
there's a drum and inside are brake shoes and when you step on the brakes
the cylinder pushes out and pushes the brake shoes that are curved against the
inside and for a long time this was the best system out there it's relatively
sealed from the elements, since the shoes are inside and this covers them, but they
have one major drawback, they tend to fade after quick repetitive usage of the
brakes as in racing where, you stop and then you speed up and stop and speed off
the corner and brake and then speed up they'll fade, so for racing and really heavy
loads they came up with these disc brakes that don't fade that much and
they also work better in water situation, because it can squeeze the water right
out as it squeezes in, where if water gets inside the drums then they really
slip and slide as they dry out, when I was young at a 1970 Ford Maverick and it had
four-wheel drum brakes and believe me especially in colder weather, if you had
drum brakes and you went through some deep water then you hit the brakes, they
would just slide cuz the water got inside and it would just slide like mad
where the disks, those pads they can squeeze it out and since they're open air
the water comes off a lot easier, now the first real use in mass production of disc
brake was in the 1940's for airplanes and for tanks, for two kind of
different reasons, but here's what they are, the disc brake systems tend to weigh
less, take up less space, so in an airplane that's a big deal, fighter
jets they want to make them as fast as possible and a big b-17 bomber hey
that's a lot of weight, so the disc brakes can take that heat when you step
on the brakes and all that weight condenses and dissipate it better than the drum
brakes could and in the tanks, there was a limited amount of space with the treads
going around, so they found that the disc brakes would fit in that smaller space
better plus, hey tanks went everywhere they went in water, mud, and you're better
off with disc brakes in a bad environment than you are with drum
brakes, now as for cars the first real disc brake use was in 1951 in a British
racing motor company, they had a Formula One car that had front disc brakes, now
disc brakes had such an advantage in racing that all the racing cars quickly
went over to disc brakes because they slam on the brakes before they hit a
corner, then they stopped on a gas and then they hit the brakes, they don't want any
fading and want them to work as well as possible and of course in a race car
weight is everything, you want to make it as light as possible so they all went to
discs, now the first American car that was mass produce it had four-wheel disc
brakes that was a 65 Chevy Corvette only makes sense a sports car, they wanted to
make the Corvette as race capable as possible, guys were racing them and to
have the absolute best performance so it was the first American car that came
with all four wheel disc brakes, so you might well ask why does this Toyota
Celica that it was made 30 years after the Corvette have discs in the front way
up here in the front, but drum brakes in the back, well of
course part of it has to do with cost, this is based on the Toyota Corolla, they always had
drum brakes in the back and are somewhat cheaper to make and it's a really low end sports
car, a lot of people wouldn't even call it a sports car, so it's got discs in the
front and drums in the back, but in terms of normal driving, it really doesn't
affect it much at all, because the front brakes especially when disc, they do over
90% of the braking of your vehicle anyway, normal driving, the main thing
that the rear brakes do, is keep the vehicle from swaying from side to side
like a wild wagon when you're braking and I'm forever getting people asking me
on my car talk or emailing me questions, oh Scotty I
got disks in the front of my car and drums in the rear should I buy a disc
conversion kit for the back brakes to make them work better and my response is always
Hey unless you're racing the thing don't waste your money. it doesn't affect them
all that much. there's still a lot of motorcycles out there that still have discs
in the front and drums on the back, because if you know anything about
driving motorcycles, you use your front brake all the time, some of the guys never even
use their rear brake, now the racers do because they're doing completely
different kinds of dynamics of normal driving on the street, a normal
motorcycle driver uses your front brake all the time that's how you slow down
and that's how you control the vehicle and other guys will ask me, hey I've got
regular disc brakes in my car, but should I put drilled or slotted rotors
on them, well again only if you're racing the
vehicle, that allows the heat to be dissipated a little bit faster because
of all the holes that the air can go through, so in a race where you're
stopping and going stopping and going they won't fade, but really for normal
driving, non slotted disk actually will stop your car faster for one time
because there's more surface area so the pads are squeezing more surface area and
the heat can be taken away faster and stop your car quicker, plus there's a big
downside to drilled and slotted discs, one they have a tendency of making noise
because you got either the slots of the holes drilled and a lot of times you can
hear and feel it as you stop and guess what that we're out a lot quicker
serious race guys hey, they change the rotors and discs after every single race
you're not gonna be doing that driving your everyday driver, so in any modern car the
system that it comes with for everyday driving it's pretty good the way that it
was designed, but let's say you were building up an old 1970 maverick like I
used to drive that had four-wheel drum brakes, in that case it would definitely
be worth your while to remove just the front drum brakes and replace them with
disc brake systems, that would stop a whole bunch better, so now you know the
truth about drum vs disc brakes, so if you never want to miss
another one of my new car repair videos, remember to ring that Bell!