Just a Rant on Drum Brakes

[artificialist]

Originally Posted By: hattaresguy
Originally Posted By: HTSS_TR
Other than lower cost, drum brake has no advantage in any category(performance, easy to check/replace ...) over disc brake.


Mercedes uses them inside the rear rotor hat for the parking brake, they seem to work OK in that application.


That is common in other cars as well.

That in mind, I often encounter one problem. A rust ridge would develop in the drum part, and removing the brake rotor was impossible without damaging the miniature brake shoes.

This even happens to cars that don't encounter road salt.

 

[HTSS_TR]

Originally Posted By: hattaresguy
Originally Posted By: HTSS_TR
Other than lower cost, drum brake has no advantage in any category(performance, easy to check/replace ...) over disc brake.


Mercedes uses them inside the rear rotor hat for the parking brake, they seem to work OK in that application.

I didn't mean parking brake shoe inside the rear rotor in many Mercedes vehicles and other makes. I mean real drum brake in place of disc brake.

 

[Vikas]

I challenge anybody to give me the cost analysis of drum brakes vs disk brakes and proving that drum brakes costs less to manufacture than disk brakes. Don't forget to add all the sundry parts in the breakdown.

This case is exactly like when phone company used to charge you extra for touch tone over pulse dialing. Unfortunately, half of the participants here do not even know what a phone company was or what touch tone meant

 

[IndyIan]

Originally Posted By: Vikas
I challenge anybody to give me the cost analysis of drum brakes vs disk brakes and proving that drum brakes costs less to manufacture than disk brakes. Don't forget to add all the sundry parts in the breakdown.

This case is exactly like when phone company used to charge you extra for touch tone over pulse dialing. Unfortunately, half of the participants here do not even know what a phone company was or what touch tone meant

Probably drums are cheaper than the discs plus parking drums on many cars/trucks. Why have two braking systems on one axle if you don't need the additional heat dissipation of discs?
I don't really care, which brakes I have on the rear axle for a road car anyways as I don't tow in the mountains. For a track car then discs become necessary, but 99.9% of cars never see 2 hard stops in a row...

 

[KrisZ]

Originally Posted By: Vikas
I challenge anybody to give me the cost analysis of drum brakes vs disk brakes and proving that drum brakes costs less to manufacture than disk brakes. Don't forget to add all the sundry parts in the breakdown.

This case is exactly like when phone company used to charge you extra for touch tone over pulse dialing. Unfortunately, half of the participants here do not even know what a phone company was or what touch tone meant



Funny, few days ago I thought just about that and it ended up with me just thinking about it. I think the reason drum brakes are cheaper is that the drum itself is much cheaper to cast and machine, the brake cylinder is also very simple, small and doesn't require tight tolerances and the rest of the parts are simple stamped steel type of components, i.e. dirt cheap to manufacture.

Discs on the other hand are more complex to cast with cooling vanes, the brake caliper and the bracket are another castings with precision machining required. The cylinder itself is another precision component also requiring a smooth finish as well as the guide pins. Add dust boots, shims and more complex, shimmed brake pads and the difference could be significant. At least that's how I see it.

 

[Vikas]

I think you have a point there and I like your explanation.

 

[HangFire]

Originally Posted By: HTSS_TR
Other than lower cost, drum brake has no advantage in any category(performance, easy to check/replace ...) over disc brake.


This is false. Big trucks have drum brakes for a reason, and that reason is more swept area can be had within any given amount of wheel/hub space.

Until someone comes up with a disc brake that has calipers and pads all the way around, or regenerative technology completely supplants brakes, we'll always have drum brakes with us.

 

[Vikas]

drum brakes can also be "self-energizing" (at least going in the forward direction); without assist, disc brakes pretty much don't work.

 

[JFK]

All of my Toyota's have had rear drum brakes and never an issue.

 

[slacktide_bitog]

Originally Posted By: HangFire
Big trucks have drum brakes for a reason, and that reason is more swept area can be had within any given amount of wheel/hub space.


US-market third-world trucks use drums because they're cheap; the same reason the transmissions aren't synchronized. Trucks in Europe have disc brakes and synchromesh (some of them are even automated manuals)

 

[hattaresguy]

Looks like you can have this axle set up either way, I suspect the disc is more money.

 

[SteveSRT8]

Originally Posted By: exranger06
All three of my Fords have rear drum brakes. I can easily lock up the rear tires (until the ABS kicks in), they last a really long time, and the parking brake works WAAYY better than any rear disc setup I've ever used. Drums on the rear are just fine in my book.

I agree as I service the drum brake equipped portions of my fleet FAR less than any with discs.

We recently sold a beautiful 05 Silverado with 126k miles on it and it had only been inspected twice as far as the rear drums go. No parts needed!

 

[Garak]

And of course, real drum brakes make a fantastic parking brake.

 

[philipp10]

Originally Posted By: Miller88
I have had more than one vehicle with rear drums and they, simply put, NEVER work after the first set wears out.

They were assembled per the factory service manual 2 months ago. The auto adjusters were working properly and not allowing the brakes to back off.

The parking brake worked (even facing up hill!) and, while I couldn't lock up the rears due to having larger tires, it stopped real well!

But, the same as every other time I have either done them myself, paid a shop to do them or had a friend do them ... they stopped working in 2 months.

I would rather have expensive screw-in piston rear calipers that seize up every other year ... they at least work for more than two months at a time.

Now it's due for new front brakes after about 30,000 miles because they have been picking up the slack for the rears.

The only reason I can think of for this third world garbage to never work is the backing plates just get too rusty and cause everything to move around. Which then results in the brakes always backing off.


How do you know they are not working?

 

[widman]

Discs have one big advantage: when driving through water they continue to work. But they are simple and effective otherwise. I doubt that many here have ever driven cars that did not have at least front discs.

If they are wearing out, they are probably dragging. Check wheel temperature with a $10 laser gun.

If the replacement shoes are not as good as original ones, buy the right ones. You can buy all types, soft, hard, etc.

 

[Kruse]

Originally Posted By: widman
I doubt that many here have ever driven cars that did not have at least front discs.


A couple of years ago, I sold a '69 Nova that had four wheel drums and no power brakes. I bet a few people on this site would be surprised at how hard the pedal had to be pushed.

 

[xtell]

Only have rear disc's on my Trans Am. My other cars and work trucks all have drum rears. Aside from having to use a torch to heat them up to get them off for break inspection, I've not had any problems with them. As others have said, the brake shoes do last a long time.

 

[Michael_P]

I prefer drums on any vehicle that will launch a boat. Disk brakes that have a tiny drum inside of the rotor does not hold a heavy boat on a steep ramp as well, which is why the big three went from disk brakes in the late 1990's back to drum brakes in the early 21'st century. Disk brakes where the caliper actually grabs the rotor is not much better. Though if you ever break an axle on a pickup with disk brakes, your truck will not vomit a tether ball court on to the road.

 

[SwampSurvivor]

Didn't realize this topic kept going.

Anyway, found the reason the drum brakes keep backing off. Turns out NONE of the hardware kits have the correct spring to hold the rocker arm in place.

There are two sets of brakes available - 9'' and 10''. I checked the 10'' hardware kit I accidentally bought a few years ago and it doesn't have the right spring either.

I have had a few sets over the years on this. They all have the wrong spring.

So, what I think I am going to have to do is go to the junkyard and find the springs off of a Jeep and see if I can find the right spring on a junkyard Jeep.

 

[CT8]

Originally Posted By: Miller88
Didn't realize this topic kept going.

Anyway, found the reason the drum brakes keep backing off. Turns out NONE of the hardware kits have the correct spring to hold the rocker arm in place.

There are two sets of brakes available - 9'' and 10''. I checked the 10'' hardware kit I accidentally bought a few years ago and it doesn't have the right spring either.

I have had a few sets over the years on this. They all have the wrong spring. That is reallt nice that you solved the problem! . Some times problems happen.congratulations

So, what I think I am going to have to do is go to the junkyard and find the springs off of a Jeep and see if I can find the right spring on a junkyard Jeep.