Drum Brakes

[psyshack]

I wont by a car anymore that has them! Its a shame there even made for automotive use anymore. And a marketing tool at that.

If drum brakes where so good they would still be on the front wheels on cars and Large aircraft would use them still. I cant imagen having drum brakes on a motorcycle now days.

Drum brakes dont deal with water worth a hoot. They have a propensity to lock due to shoe shift in the drum. You have springs that fail alot more often that folks want to admit. They only use about 1/2 of the shoe surface in braking. Just look at the shoes sometime. Only the top half of the show wears. The bottom half is barely used unless there is a lower cam that moves the lower part of the shoe into action. also if you look at a worn shoe you more than likely will see that the inner part is worn a bit more than the outer part. This is due to flex in the drum that happens during braking.

My brother is a tool and die man and shop manager. He quotes jobs makes dies runs production, buys matrials and such.

We talked about this very same subject. Hes with me on this issue and cant figure out why cars are even built with drums anymore. So I asked him to do a mock quote on production of the two brake systems. Are drum brakes really cheaper to produce than disk? I also asked my father inlaw the same question as he owns a foundry. So casting the drums, rotors and calipers would be right up his alley. he and my brother worked on this as if they where both supplying for a large automive company.

The answer was socking! Over all drum brakes cost more to produce!

The disk and caliper casting cost more to produce than the drum. But there also a much higher quality casting and peice of work. Then it ends. The back plate of a drum brake cost alot more to stamp ot then a light weight sheild used on on a disk brake system. The brake pads of a disk brake cost almost half as much as a drum shoe to produce. Then theres the springs, pins and other small hardware in a drum system. Spring winding machines cost alot to run and maintain at a level of producing brake parts. Theres alot of quality control issues from bulk spring wire stock to production of said springs. Alot of springs if tested right would be culit. The piston in a caliper is cheaper to make than the pistons in a common drum brake. Valving and control circuts are about the same for both.

In there little excersise they came up with drum brakes costing about 20% more to produce than disk brakes. Also there was more product liablity in the drum brake systems.

I think market dept's use drum and disk brakes as a trim adder for a excuse to charge more for something that cost less to produce. IMHO drum brakes should never be used on a new production auto.

Drum brakes and disk brakes are kinda like floresent lighting and power compac floresent lighting. Or even LCD panels verses CRT.

Older flo-light systems cost more to make than compac-flo-light systems. The newer lightes put out more light per watt used! A electronic ballist is far cheaper to make than a old style ballist and the bulb production is basicly the same.

Same with LCD's and CRT's. A CRT cost far more to make than a LCD. Just making the glass tube cost more than anything in a LCD panel of the same size.

In the LCD/CRT issue Im guilty of buying a CRT recently over a LCD. No way in hell Im paying 2500 bucks for a 32" wide LCD panel to watch TV on. So I purchased a 36" Sony Vega CRT for 700 bucks. I will never ever move that god awful heavy TV again. I will take it out of this house in peices when its time comes and it leaves.

But I will never purchase a car or truck again with drum brakes. My last drum brake purchase was my 00 Ranger. I only bought it new cause I got it for under 15k new. And truley wish I had not bought it. The drums are awful on it.

[Matt Timion]

I understand a lot of your issue with drum brakes. I'm shocked that new cars are made with them, as disc brakes require less maintenance and are easier to work on.

That being said, I will not be swapping rear disc brakes onto my car. There is a weight differerence of around 25lbs between the disc brakes and the drum brakes. Every little bit of unsprung weight that I can save the better.

[Compaq888]

I don't know what you are complaining about. The only problem i have with brakes is I think ABS should be standard on all cars.

I have drum for the rear and discs for the front. My front disc brakes are huge. I can easily lock my tires at any speed, these *****es hold. I erased my last set of tires when I braked on the freeway to avoid a dog. Since then I have gotten rid of my warped disc problem and upgraded to racing pads. The pads are a little bit too much, they grip a lot more.

I'm fine with drum brakes in the rear, just make ABS because evrytime I slam the brakes my tires gets erased.

[Matt Timion]

Originally Posted by Compaq888

I'm fine with drum brakes in the rear, just make ABS because evrytime I slam the brakes my tires gets erased.

your tires vanish whenever you slam on the brakes? how weird.

[Compaq888]

Originally Posted by Matt Timion

your tires vanish whenever you slam on the brakes? how weird.

Yea, with the new brakes it's even worse. If I slam at 5mph I can give anybody sitting in the car whiplash.

[psyshack]

Originally Posted by Compaq888

Yea, with the new brakes it's even worse. If I slam at 5mph I can give anybody sitting in the car whiplash.

Compaq

You need to learn to quiver. Folks have known for years that a locked up wheel dosent stop as good as a ever so slightly rotating wheel. Train engineers, truck drivers and race car drivers lives have depended on it for years. ABS is the modern I dont have to think to hit the brakes system. And its great if people use it right.

The quiver is simply that. If you hit the brakes hard you figure out just how you have to land your foot on the pedal at hard pressures to make your leg quiver. This has a effect on the braking system like ABS. The slight quiver helps you to not lock up the brakes so early, but still allow max braking. Quiver isnt the best way to do it. Buts it the simplist. Once you find the place in your foot and leg position that causes it. It will become natural to you.

[Compaq888]

Originally Posted by psyshack

Compaq

You need to learn to quiver. Folks have known for years that a locked up wheel dosent stop as good as a ever so slightly rotating wheel. Train engineers, truck drivers and race car drivers lives have depended on it for years. ABS is the modern I dont have to think to hit the brakes system. And its great if people use it right.

The quiver is simply that. If you hit the brakes hard you figure out just how you have to land your foot on the pedal at hard pressures to make your leg quiver. This has a effect on the braking system like ABS. The slight quiver helps you to not lock up the brakes so early, but still allow max braking. Quiver isnt the best way to do it. Buts it the simplist. Once you find the place in your foot and leg position that causes it. It will become natural to you.

you mean make my leg spasm so it acts like a ABS system?

[MetroMPG]

The downside to disk brakes for me is that they're open to the elements. When you don't drive every day (and then when you do drive, you don't use the brakes much or very hard) the disk surface rusts.

Streamlining my wheel covers helped with this a little, but the front brakes are still kind of grumbly for the first km or so when I fire up the flea.

[SVOboy]

I don't mind my drums because they can stop my car. I think I should go and say I'll never buy another car over 2100 pounds,

I could swap as well, but the weight isn't worth it to me.

I'm also not a fan of ABS for myself. I am in general cuz it keeps most "slam-the-brakers" from hitting me, but I have found the point where I can stop without locking up the brakes.

*shrug*

Static friction > kinetic friction.

[tomauto]

How much more weight would rear disk brakes add compared to a drum brake setup. I was wanting to add disks in the back of my civic. I never thought of the extra rotating mass.

[Matt Timion]

Originally Posted by tomauto

How much more weight would rear disk brakes add compared to a drum brake setup. I was wanting to add disks in the back of my civic. I never thought of the extra rotating mass.

It's about a 25lbs difference overall from what I understand.

[Ryland]

I don't like disk brakes because they alwas drag, it is part of their design to have close pads, if they came up with a design for disk brakes that was lighter then drums, and that the pads were able to fully retract, then I would think about them, but as they are they weigh more, and slow you down, try it, coast to a stope, and feel your wheels, if you have disk brakes they will all be warm, and the drums cold.
how much more does it cost to put a cable operated hand brake on a disk brake set up? was that included in your cost comparison?

I agree that disk brakes on the front of a motorcycle are nice, I've riden ones with every configuration, altho I never had an issue with the duel trailing pad front drum brake on my honda, the nicest thing about disk brakes on the front is that it's really hard to lock up the front wheel, and that is the only reason I would want them on a car or a motorcycle, but just like automatic transmitions, disk brakes are an extreamly problem filled part, I would say they require at least twice as much. attention/matence/tossing at of money then drums, altho

[thisisntjared]

drum brakes have too much play.

[tomauto]

I would love a firmer pedal. It just feels safer. That is one of my main quibbles about drum brakes...the soft feel of them is just unassuring. I had my brakes resurfaced, bled, and resurfaced last year. Still soft. It was dissapointing. I haven't done any shopping, but I know I would want it at some point.

[katman]

It's possible that your flex lines are doing just that! They do go bad and get weak and will expand under pressure. You could switch to braided steel lines for a rock hard peddle.

[philmcneal]

good points everyone, but in the end regen owns all!

There was a toyota prius II at over 100,000 km that showed no signed in brake wear unless you put a microscope to it. Regen braking is truly the bomb and all drums should be installed for maximum weight reduction! Well I save gas so I barely go fast anyway so my front discs and rear drums are good enough.

[thisisntjared]

i drove a car with 4 corner drums recently. horribly unsafe. i would take out airbags and seatbelts before going drums on all 4 corners. i dont understand how there is an argument for all drums in a street car.

even with stainless brake lines, it still will have the play, all drums do this. it is the nature of the beast.

[Ryland]

haveing drum brakes on all 4 corners is not something that I would push for, drum brakes are to good at locking up wheels, where disk brakes are better at slowing you down without lock up, disk brakes make lousy parking brakes from what I've seen, and it's nice not to have the wheels you use to steeer with locking up.

as for disk brake being cheaper, to replace my entire brake system,
drum brakes cost $187.30 per wheel to buy all new brake drums, wheel bearings, mud guards, brake shoes for the rear.
disk brakes cost $325.97 per wheel for disks, calipers, bearings, pads, guards.
they still use drum brakes on the rear of vehicles like the Honda Insight, and they went to great laingths to make that vehicle safe, and light weight.

[tomauto]

Not many parts are actually available for my 4 door civic. They are few and far between. Anybody know any decent brands??

[Gary Palmer]

I have been able to get a lot of the item's for my 89 Honda, from a place called Autohaus AZ. They are available in Phoenix, or over the internet. So far all of the part's have been very high quality, at very reasonable price's, which is not easy to do for Honda part's, generally. They don't alway's have every thing I have needed, but I've gotten all of my ring's, bearing's, head gasket's, water pump's, oil pump's and thing's like that from them and I've been very happy with the quality. (This is not a pitch, it's just my experience!)

[Ryland]

I get alot of my parts from honda dealers, http://www.hondaautomotiveparts.com/ is who I got the price for brake parts from, their 3-4 day shipping however takes around 12 days.

[Matt Timion]

Originally Posted by thisisntjared

i drove a car with 4 corner drums recently. horribly unsafe. i would take out airbags and seatbelts before going drums on all 4 corners. i dont understand how there is an argument for all drums in a street car.

even with stainless brake lines, it still will have the play, all drums do this. it is the nature of the beast.

Even my n600 has front disc brakes. Sure, they're as tiny as hell, but they're disc brakes.

Just imagine how small the rotors have to be to fit underneath the 10 inch rims.

[omgwtfbyobbq]

Ditto, for most of the general population's driving needs on city streets, drums are fine. I suppose during race conditions drums can heat up quite a bit, but given advances in materials since the disk brake was introduced, fade isn't what it used to be and they're actually suitable for some racing as well. According to the d00d that built this car.

Originally Posted by WackyWabbitRacer

Are rear brake drums adequate for performance braking?

The answer is yes with the right type of shoes.

As required by SCCA Production rules, I use the stock rear drum brakes on my H-Production road racer, plus the 9.4 inch solid rotors on the front.

I am sure that my race Wabbit gets more braking abuse than any street daily driver, and I really don't have any brake problems with the solid rotors and rear drums. However I do use performance race front pads and performance rear shoes.

The most important thing is maintaining the entire braking system, front and rear. With new rear brake cylinders, shoes, and drums, plus frequent fluid flushes, I believe that virtually all of our A1 Dubs do not require rear disk brakes, except in very rare situations.

Regards, WWR.

Originally Posted by Edmunds

In today's automotive pantheon, it's not uncommon to find four-wheel disc brakes as standard equipment on medium-priced, non performance-oriented models. The majority of new vehicles, however, continue to utilize a front-disc/rear-drum brake setup. What does this say about the current state of braking systems? Are these manufacturers sacrificing vehicle safety in order to save a few bucks by installing disc brakes on only the front wheels?

While a "yes" answer would certainly be great for increasing Town Hall traffic, the truth is that today's disc/drum setups are completely adequate for the majority of new cars. Remember that both disc and drum brake design has been vastly improved in the last 20 years. In fact, the current rear drum brake systems on today's cars would provide better stopping performance then the front disc setups of the '70s. And today's front disc brakes are truly exceptional in terms of stopping power. Combined with the fact that between 60 and 90 percent of a vehicle's stopping power comes from the front wheels, it's clear that a well-designed, modern drum brake is all that's required for most rear wheel brake duty.

[onegammyleg]

Originally Posted by theclencher

I can't believe the guys on here raggin' on drum brakes- that's insane!

All of your points were exactly spot on.
For FE machine drums are the way to go !!!! no question about it.

Discs brakes rely on the disc knocking the pads back into the caliper for clearance drums dont.
This means there is ALWAYS more resistance on a disc brake setup as the brakes always drag a little.

With steel lined vented alloy drums supporting a twin leading shoe arrangement stopping power is good.

Manufacturers went to discs BECAUSE IT WAS CHEAPER FOR THEM !

[onegammyleg]

The corvair probably would have locked up anyway.(as you say)
Race car disc systems are manufacured to very high standards and are not the same as on our shopping trolleys.
If we had these brakes ,OK , discs are kool , but we dont., we have cheap immitations.
Its sure that because of racing success discs have been encouraged to put onto passenger cars also . but the cost of making a brake system (at teh wheels end) with only a few moving parts is a lot more economical idea than a drum setup which may have 10 or 20 moving peices.

As you say , drums can stop well.
On the front twin leading shoes have a power assistance type of effect often meaning no vac booster is required (especially on a light car)

[JanGeo]

Originally Posted by tomauto

I would love a firmer pedal. It just feels safer. That is one of my main quibbles about drum brakes...the soft feel of them is just unassuring. I had my brakes resurfaced, bled, and resurfaced last year. Still soft. It was dissapointing. I haven't done any shopping, but I know I would want it at some point.

Hey I think I have a quick fix for your problem . . . go up a hill where you can stop and roll backwards without anyone behind you and pump your brakes firmly several times. This adjusts your rear drum brake shoes and should take out most of the pedal travel, then as they wear and you do it a few more times they will get firmer.

[onegammyleg]

Many , if not most drum brakes get adjusted when you apply the handbrake.

[Silveredwings]

Originally Posted by onegammyleg

Many , if not most drum brakes get adjusted when you apply the handbrake.

True, but the old chevys adjusted when you backup and hit the brakes.

BMWs have disks in the front and rear, and an set of extra drums in the back for the hand brake.

[onegammyleg]

This is a vented alloy drum with fins if some readers are not familiar with what I have been talking about.



On small FE cars they could return.
Remember that in the old days machining and materials werent as good as what can be done today.

Ime sure if they put their thinking caps on they could make a nice drum system now days.

[jolt-tsp]

Lets not get too carried away one way or the other. Drums are better for FE, but should never be on the front of a car anymore. A pair of drums on the back never hurt anyone (unless you're racing), and they normally make for a much more effective e-brake.

For street driving, there should be nothing wrong with rear drums. If stopping in rain or dry is an issue, then there is probably a problem with the brakes or with the tires. Many people like to overlook the tire. If you are running 155's for FE, don't get pissed at your drums if you're not stopping. Short of running an r-compound tire, 155 mm is just not enough of a contact patch to stop your car on the dime (unless your car is in the sub 1800 lbs range).

The drum brake is going to be lighter and brake harder initially than a disc brake of equal size because their is a greater friction area. However, this causes heat build-up faster and degrades the performance very quickly. Rear brakes never support much weight during breaking and therefore will not heat up as fast. When braking the majority of the weight goes to the front of your vehicle, so drums in the front will heat up very quickly and can degrade your braking performance in just one hard stop.

I didn't really get any sleep last night so don't just my ability to string words together too harshly. :-p