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What's with the two calipers on each rear wheel?

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34K views 11 replies 7 participants last post by  MacGeek  
yes its the e parking brake caliper. Supercars have always used a two caliper system as do motorcycles with E-parking brakes. Some of the cars we've seen with electronic parking brakes hide the second caliper because they use a drum/disc setup... its also possible we just notice it as often because were not always looking for it...
 
Thanks. There must be a good reason for it, but it escapes me. Might simply have to do with multi-piston calipers. I'm familiar with the drum-in-hat setups... and my $20,000 Pontiac Solstice can manage an e-brake and hydraulic caliper all in one, but the rears are single pot.
off the top of my head I would imagine that the difference could be that the e-brake is no longer mechanical, therefore isn't compatible with hydraulic brakes. I'm not sure, but my thinking is that the electronic e brake is essentialy brake by wire... the comand is sent to module, which then executes...

Other then that I've got nothing ahaha
 
I assume that it is in replacement of another type of brake, a drum brake or something else. Given the focus on weight saving I am guessing these brakes are either way better than other options, or not weighing much more at all actually.
No...

This has nothing to do with weight saving, nor are we looking at a NEW type of brake. Its a simple rear wheel disc featuring an electronic parking brake. For the most part ANYTHING using a purely electrical parking brake will have a second caliper. just like once upon a time a mechanical cable used to run back there for when you pulled the handle up, now there just needs to be a second caliper for when you press that parking brake button... it cant rely on hydraulic pressure like your car does when you're braking it, nor can it rely on the simple mechanical cable...