Why no four-wheel disk breaks?

Subjective feel and actual stopping distance are quite different. With all the electronic gadgetry like EBD, ABS, VSC and auto-LSD, you pretty much have to treat it like a by-wire system. The brakes will do something different than what the pedal is doing...
Every single time I had to do a panic stop on the highway from 75 mph, the truck stopped well enough.

 

but aahhh... have you ever had the fun and joy of driving front-drum cars in rain? what fun, driving with no brakes. Pumping brakes after every puddle to dry them out and know when they return. And when they DO return, never both wheels at same time: they pull HARD until both front drums are fully dry. Drums may be great in grease, but they are terrible in water and water happens a lot more frequent on the road than grease!

Drum's costs ALONE? maybe. But disk brake parts require more, and greater precision, machining so not as much less as you might think. A disk/drum combo for an effective e-brake is doubtless more expensive, fully assembled.

 

I have often wondered about drum brakes having more stopping ability. Disk brakes can stop quickly but heat up fast. Cooling is a problem with disk brakes. (http://www.youtube.com/watch?v=22t7pMSXVQ0) I have a friend whose brother owns a brake shop that maintains brakes for semi trucks. All those semi-trailers and double axle tractor brakes are huge drum brakes. I guess they have more surface area than disk brakes.

I am not an expert on this but I would think that disk in the front for quick stopping is a good design. Drums in the back for heavy loads when towing and hauling a good design. Some here have modified the rear brakes on their Tacomas to disk. I feel no need. I usually get 3 pairs of front brake pads to every 1 set of rears - regardless if they are disk or drum.

 

No...it has to be a tie between 'which lift?' and 'does this cheezy mod look good?'
Disk brakes brakes are effectively used on many light trucks and aside from dissipating heat better, they can be more effectively modulated, not that it matters in a truck like ours.

 

my tacoma has the worst brakes of any truck i currently drive. i have access to a chevy colorado, and my half ton silverado. coming from my tacoma and into the other trucks, the very first time i hit the brake, i do so violently. i overdo it bigtime. one time, and my brain re-calibrates and i go merrily on my way.

the tacoma stops fine, but the pedal is mushy by comparison. i do not blame it on the drums in the rear. mathematically, the fronts do most of the work anyways.

 

Drum brakes and disc brakes are used on semis. Usually disc only on the tractor steer wheels. They seize up very quickly from disuse. They are more maintenance intensive than drum brakes, but provide better braking and fade resistance. The flutes between the friction surfaces provide far more surface area to dissapate heat. Couple that with the flutes ability to act as a fan, which makes it evem more superior to the drum brake.
Drum brakes lock much easier than disc brakes.
GM uses a cam operated parking brake that actuates a screw inside the piston. It does not use a separate drum.

 

You sure they do that on their larger vehicles too? like Yukons or Silverado p/ups? I know that's common on almost everybody's smaller vehicles but that design barely holds even something as small as a Civic or Golf. Disks require a LOT more brake force than an equivalent stopping power drum does because drum shoes are what is called 'self-servoing'.

I also know my Rodeo and Trooper II both had disk/drum combo's and Isuzu teamed real closely with GM and used a lot of GM designs and accessories on them.

 

I don't know about gm's larger vehicles, the smaller ones I know had them for sure. Maybe the design is limited to smaller vehicles, IDK.

I am aware of the two differant styles of drum brakes, most use the servo type. They usually have one shoe larger than the other. The self energizing aspect of servo type drum brakes is what makes them more prone to locking.

 

thanks for the neg rep, db.

 

You're welcome Zombie...well deserved!

To everyone else with a serious reply, thanks. Just looking for some honest input.

 

Next time leave your name so the receiving end will know the scum bag that did it

 

Why does everyone always defend the Tacoma with "It will cost more money with such and such?" Don't get me wrong I love my truck but it's not like it's the cheapest in it's class and does not have as many bells and whistles as others in it's class at similar pricing. I can't see disk brakes breaking the sales price on these trucks. I paid the same for my wifes 4-Runner which has 4 wheel disk brakes, leather, navigation, sunroof and has much better sound proofing in the engine bay so it doesn't sound like I am in a diesel when pulling through a drive-thru window. I am with the OP and was dumbfounded by the lack of disk brakes in the rear in the year 2010. Again, I love my truck but I think the brakes could use much improvement. My wife always bitches at me when we take her truck out because the first few lights or stop signs I nearly put her through the windshield because I am used to having to really be on the pedal to get the Taco to stop compared to the Runner and as someone else mentioned, with a heavy load the brake performance is lack luster at best. I'm sure I will get flamed for my post but I am just being honest rather than go on the defensive as if I were the one who designed the truck. I love my Taco but the longer I own it the more I realize I over paid for it but at the same time it will also last longer than anything else I looked at in it's class and even in the full size class. It's just too bad I probably won;t own it long enough to get the perks of that since I tend to get bored easy and change vehicles every 4 to 5 years.

 

You gave negative rep for that?? It was a joke, if you knew how to spell he wouldn't have said it.

I'm sure you'll make a lot of friends here...

 

his comment

looks like he can't make whole sentences either

 

I have twi VWs with disk all around. What a pain, sometimes the rotors last no longer than the pads.

I think chevy tried disk on some of their trucks and had numerous warranty repairs (I am not equating chevy with tacoma, just what I heard) and issues in the back that would not be present with drums.

I think my Tacoma stops pretty solid, pedal feel is good.

 

here, quit bitchin
http://tundraracing.com/rbck.htm

or if you really really want to stop
http://tundraracing.com/proseriesprerunner.htm

 

oh well, if it dont stop very good then atleast we wont have to hear the complaining any more.

 

Several people here have gotten it wrong about drum's having better stopping power. Totally wrong. Disc's have better stopping power while drum's have better HOLDING power. That's why the disc's are on the front as over half of the braking on any vehicle is done by the front wheels... especially a pickup truck where most of the weight is up front.

Personally I like the disc/drum setup and just reciently replaced my front disc's with slotted and drilled rotors after 100,000 miles on the origional factory pads and rotors. Go tell me they're crap now??? I pull a travel trailer that's 5500# loaded and the truck braking is great (and yes the trailer has brakes as well) The fact that the rear is drum is nice because with a heavy load on a hill like that you're going to have better holding power, yet stopping with a heavy load your disc's will give you the confidence to stop.

 

great post j4x4ar. What aftermarket rotors did you go with?

 

All drums are self-servoing. Differences are a single-servo where only one shoe is self-servo and dual servo where both shoes are. Dual servo is usually found on front drum set ups.

It's not really the servoing that causes lockups, it's poorly adjusted brakes and defective parts (especially weak return springs) that do. Also contamination as from leaking wheel cylinders and/or axle seals. Servoing just makes it easy to notice.