Drum Brakes: Ugh...

I hate drum brakes. Specifically, I hate working on them. It bothers me that it's still possible to buy a new vehicle (even a truck) with these things on them.

It's getting cold and the rear brakes on my truck are clearly out of round. I checked the price of replacement drums, considered the time and cost of removing them myself, having them turned and then reinstalling them and I'm starting to consider the option of just dropping it off at a local shop and paying them to deal with the whole mess.

I also hate the thought of paying someone else to do a job that I know I can do myself.

I have not had to deal with real drum brakes in about 12 years. My BMW has them on the rear for the handbrake, but that is a rare job.

personally, I hate them

I know they are adequate for most situations but I too hate to work on them. Give me disks anyday just for the convenience factor.

And drums are so much dirtier to work on too with the resultant health hazards even tho they don't contain asbestos anymore, do they?

I refuse to work on drum brakes. I have them on the rear of my DD. If they need service, I will swap them to discs, or gladly pay a shop to service them. Simply not worth the frustration.

I don't mind working on them at all. I just went through the drums on my MG this afternoon and actually considered it relaxing. Guess I'm strange.

Whiners.

Drums are cake, and they last almost indefinitely. Learn to recognize a good thing when you see it.

Zomby woof wrote: Whiners. Drums are cake, and they last almost indefinitely. Learn to recognize a good thing when you see it.

cha-ching

Zomby woof wrote: Whiners. Drums are cake, and they last almost indefinitely. Learn to recognize a good thing when you see it.

They are just a bunch of girlymen.

Sadly, I'm not sure where to get semimetallic shoes to replace the Abex ones in my Camaro. Is it Porterfield that still makes them?

The best moment of the e30 build so far was replacing the drums with some 325i rear discs......

GM drum brakes are probably the easiest I've ever dealt with, only because they haven't changed design in 50 years.

I just did a drum brake job on a '70 Subie 360 a couple weeks ago. Was pretty damn easy too.

I make my living with drum brakes.

Everything at work is 1960's or older.

Most people don't realise there is more to a drum brake job than stuffing in new shoes, turning the drums and setting the adjusters.

I can't make them better than discs but I can make them stop the car in a big hurry and in a straight line.

Shawn

I can work on drum brakes, but I'd rather not.

While I like older cars, I prefer to deep-six drum brakes, carburetors, and points ignition... All outdated, and I see no reason to live with their shortcomings. I'll give drums on the rear the faint praise of being the least unpleasant of the items mentioned.

And although I've learned to deal with them, bonus negative points to VW for putting A1 and A2 (and beyond? I wouldn't know) rear wheel bearings directly in the drums, so you have to pull all that business apart to work on the brakes.

Trans_Maro wrote: Most people don't realise there is more to a drum brake job than stuffing in new shoes, turning the drums and setting the adjusters. I can't make them better than discs but I can make them stop the car in a big hurry and in a straight line. Shawn

care to elaborate a bit?

I don't mind them typically... although the first time I worked on them they did intimidate me a bit and disc are far easier to change pads on...

Someone should make some cross drilled and slotted drums as a joke.

BoostedBrandon wrote: Someone should make some cross drilled and slotted drums as a joke.

Uhh...

Drilled drums have been around for a long time....

Ventilated backing plates help too.

donalson wrote: care to elaborate a bit? I don't mind them typically... although the first time I worked on them they did intimidate me a bit and disc are far easier to change pads on...

No problem.

We usually tear down a drum system completely when we swap shoes.

Measure the drum, turn if necessary.

Usually we replace the springs if they look old. Often one or two will be getting weak and can cause the shoes to sit in the drums unevenly.

Check the pads on the backing plates where the shoes ride, often there is a notch worn in them from the shoe rubbing. This notch can cause the shoes to hang up and apply unevenly causing a pull.

Grind and smooth the pad if there is enough material, replace the backing plate if not. If no backing plate is available, weld and fill the notch in the pad and smooth.

Use brake grease on all point where the shoe contacts the pivot and backing plate to ensure that everything moves smooth.

Some drum brakes have pivots with an eccentric, these can be rotated to center the shoes in the drum.

Make sure the adjusters are lubed and working well.

If the drums have been machined, arc the shoes to fit the drum and provide maximum surface contact. We have an arcing machine that will grind the shoes to fit the worn drums.

If the customer wants higher performance without swapping to discs, we can ventilate the drums and backing plates.

Get a hole saw and drill about a 1" hole in the face of the drum, in between each of the stud holes, outboard of the wheel flange.

Vent the back plate by drilling holes in the non-contact, non-structural areas or cut the area out entirely and install a screen.

You can drill the drum contact surface as well but just like disc brakes, it's unnecessary with modern lining material and removes thermal mass from the drums so they don't cool as well.

Remember drums have far more area in contact with the brake material than discs do. The advantage with discs is higher pressures and much better cooling.

That being said, Pontiac and Buick both had finned aluminum drum systems that were every bit as good as discs of the same time period.

Shawn

Streetwiseguy wrote: They are just a bunch of girlymen. Sadly, I'm not sure where to get semimetallic shoes to replace the Abex ones in my Camaro. Is it Porterfield that still makes them?

Tried the Porterfield R4 compound on the rear of my Dart, they weren't bad but look like they'll only last for about 2.5 hours of track time at Summit Point. I just sent two sets of shoes off to Carbotech to get relined with something that is a better match for their XP12 compound (what I plan to run on the front disks). I'll be calling them on Tuesday. If Carbotech can't help or the linings don't work out well in practice, I may go back to Porterfield for their endurance compound.

Also adding scoops and ducting to the backing plates and considering drilling the drum's sides for vetalation as descibed above by Trans_Maro.

That said, I converted my '66 Mustang to four wheel disk back n the late 1980s.

Dave

Zomby woof wrote: Whiners. Drums are cake, and they last almost indefinitely. Learn to recognize a good thing when you see it.

Not only cheap and easy there almost always lighter then the disk people toss on.

I didn't have a problem when I replaced the shoes on mine. The only specialized tools I used was a mechanic's pick to pull the springs into the right places. And I'll probably never have to do it again, considering the originals lasted 140K miles.

I never said that they weren't cheap, or even that they weren't a suitable choice for the back end of many vehicles, particularly trucks. I just said that I don't care to work on them.

Drums are easy to work on and in many cases do not need to be replaced with discs. For instance, the Jensen Healey has them on the rear and I see no need to change those, I can't make them overheat in street driving. The Jensenator has 4 wheel disc because I want them to run cooler when I finally get a chance to do a track day and be able to make quick/easy pad changes. The Trooper has 4 wheel disc as well, I prefer them for towing because if they do overheat they cool quickly (drums hold in heat). That was one of my biggest gripes about my Cherokee; towing an enclosed trailer that weighed ~3k pounds, the brakes would get hot and the pedal drop like a rock VERY quckly and it took a long time for them to recover. The Trooper does not have that problem.

A little tip for those of you that are drum disadvantaged. Pull the phone out of your pocket and snap a pic before you tear them down. That's how I taught my son to do drum brake jobs, and he does them like an old timer now.

Ugh. The jeep has rear drum and could use servicing. Do not want.

Trans_Maro wrote: No problem. We usually tear down a drum system completely when we swap shoes. Measure the drum, turn if necessary. Usually we replace the springs if they look old. Often one or two will be getting weak and can cause the shoes to sit in the drums unevenly. Check the pads on the backing plates where the shoes ride, often there is a notch worn in them from the shoe rubbing. This notch can cause the shoes to hang up and apply unevenly causing a pull. Grind and smooth the pad if there is enough material, replace the backing plate if not. If no backing plate is available, weld and fill the notch in the pad and smooth. Use brake grease on all point where the shoe contacts the pivot and backing plate to ensure that everything moves smooth. Some drum brakes have pivots with an eccentric, these can be rotated to center the shoes in the drum. Make sure the adjusters are lubed and working well. If the drums have been machined, arc the shoes to fit the drum and provide maximum surface contact. We have an arcing machine that will grind the shoes to fit the worn drums. If the customer wants higher performance without swapping to discs, we can ventilate the drums and backing plates. Get a hole saw and drill about a 1" hole in the face of the drum, in between each of the stud holes, outboard of the wheel flange. Vent the back plate by drilling holes in the non-contact, non-structural areas or cut the area out entirely and install a screen. You can drill the drum contact surface as well but just like disc brakes, it's unnecessary with modern lining material and removes thermal mass from the drums so they don't cool as well. Remember drums have far more area in contact with the brake material than discs do. The advantage with discs is higher pressures and much better cooling. That being said, Pontiac and Buick both had finned aluminum drum systems that were every bit as good as discs of the same time period. Shawn

I rest my case, give me disks any day!

Zomby woof wrote: A little tip for those of you that are drum disadvantaged. Pull the phone out of your pocket and snap a pic before you tear them down. That's how I taught my son to do drum brake jobs, and he does them like an old timer now.

I'm olde skool, when I leared brake repair we didn't have camera phones because the dinosaurs ate them all. So after screwing up the first time way back when I learned to just do them one side at a time.