Rear Disk Worth It?

[MustGoFaster]

Maybe there is a difference between looking at pictures and reading descriptions and real life. For example, this Electric Park Brake | TRW Automotive seems to indicate weight saving is a reason to use the electronic parking brake system. But since TRW is a supplier to the auto industry, what could they know?


Laborsmith

Nah man, I'm looking at the service information provided by GM for the Cadillac CTS that is in service now. I'm not saying that it's going to be same for all vehicles thats just the first vehicle I could think of that has an electric system that I can look up in SI.

 

[ChrisJ]

You know what worries me.
The whole reason, the original reason behind the parking brake, I mean, besides parking was so you had an entirely separately braking systems for emergencies. The Ford model A originally failed because it did not have this in the late 1920s and had to have it added.

So now, besides drive by wire and hydraulic brakes which the computer can control, now your emergency brake will also be controlled by the computer. The one last direct connection you had to the brakes, gone.

I don't know if it still holds true, but just a few years ago if you got a minor leak on either your front, or back brakes your entire system could and usually would loose pressure as air would leak between front\back sections while puming the pedal. I blew a rear brake line once on my 92 pickup and was lucky it blew so badly because it 100% disabled the rear brakes. Had it just been a pin hole it would have been possible to loose all four (both front and back) brakes.

Don't know if this holds true with electronic brake distribution and what not?


In response to the original post, rear drums work great in my opinion. The ONLY downside is you need to stop firm while backing up occasionally to keep them adjusted and ride the brakes a little after going through deep water.

You do that and you'll never care about them being drums. Like others said, drums are fine.

 

[RSTURBO]

It all depends on how your using the car. If you drive normal for fuel economy like many here on the board then drums are fine. Personally i max out the brakes on my RS on a regular basis. High speed runs, heavy braking before cornering ect. The rear discs do give firmer pedal feel under aggressive driving and dissipate heat better. But ive been to racing school and have drag raced/autocrossed for 23 years so i like to depend on newer technology for extreme conditions.

 

[ss2000slp]

Figured I'd chime in on both subjects here. One nice benefit to the drum brakes I believe was stated earlier. Ease of service. True, some setups can be a pain to work on, but I have seen many cars (my shop works on every make) go well over 100k with original shoes in the rear with just periodic cleaning and adjusting. As far as the e-parking brake, don't know the setup GM will use, but I know we needed a $10,000 snap on verus scan tool to retract the piston on the rear calipers of an 07 Audi.

 

[ss2000slp]

One other benefit to drums. Here in the north east, about half the time we do front brakes we end up having to replace the rotors simply because of the rust buildup. Very rarely do we have to replace brake drums. So that can make a substantial savings in parts cost when replacing brakes.

 

[AxelRipper]

Bit of an insight here into the eE-brake setup. I'm not 100% sure how GM does it, but I did a bit of a seminar/drive thing with one of the suppliers last year and they were showcasing their e-brake system. What their system had was a setup where the initial slowing down would be done with the ABS system (keep in mind on modern ABS systems, each corner is separate and independently controlled via the ABS block). This was actually far safer in an emergency situation than your standard e-brake as it acted as a normal ABS system, actuating all available tires in a controlled manner, no lockup, still steerable. When the car was slowed enough then their actual "parking brake" system activated. This (on their setup anyways) was a worm gear that pressed on the rear caliper piston, positively holding the piston out completely independent of the normal brake system. I would have to imagine that it is also programmed in that in case for some reason your entire ABS block is sheared from all of its lines while you're driving that these would be able to slow the car down.

If you don't believe this works, then get a car with an electric e-brake in a parking lot sometime, get to about 15-20 (hell, 45) and grab the button.