rudypoochris Posted January 16, 2007 Share Posted January 16, 2007 I am just wondering why manufacturers continue to use drum brakes rather frequently on the rear of cars. People seem to say it is due to the drum brakes cheaper cost and less complex parking brake setup... Is that really true? Is the cost that much less? One would think it would be easier to make a disc setup than drums. On trucks and buses which would need very good brakes, drums seem to often be used. Is it even then that the manufacturers are trying to cost cut? Do drums have a larger pad area allowing for better initial bite and performance at the expense of repeatability? I believe drums require less line pressure to operate if setup correctly, is this a possible reason why? To gain more of a braking advantage? Do their engines not provide sufficent vacuum? Thanks! Quote Link to comment Share on other sites More sharing options...
Brett6485 Posted January 17, 2007 Share Posted January 17, 2007 Drums are used on big vehicles cause of surface area. You can get a lot out of a drum and it wont fade like a disc will. Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted January 17, 2007 Author Share Posted January 17, 2007 Drums are used on big vehicles cause of surface area. You can get a lot out of a drum and it wont fade like a disc will. Interesting.... I have heard quite the opposite about fade resistance... I would believe that a drum with its larger mass could soak up more heat on a one time panic stop but I am sure over any amount of time they can;t keep up with a vented disc. The larger surface area would also be good for one time panis stops. Quote Link to comment Share on other sites More sharing options...
Brett6485 Posted January 17, 2007 Share Posted January 17, 2007 Think of it this way, you want bigger disc you get a bigger rotor, it's a height thing. So you need a bigger rim with a more expensive tire. It gets costly quick. For drums it's just more width, something a large truck and big rig has lots of space for. Also drum pads last longer than truck ones, so there is less maintance involved. That make more sense? Quote Link to comment Share on other sites More sharing options...
johnc Posted January 17, 2007 Share Posted January 17, 2007 Drums are used on big vehicles cause of surface area. You can get a lot out of a drum and it wont fade like a disc will. And that's why large truck manufacturers are switching to disks? Drum brakes are generally cheaper to manufactur then disks - that's the main reason they are still used on lower priced cars and trucks. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted January 17, 2007 Share Posted January 17, 2007 My understanding of the fade issue with drums is that the open side of the drum expands more than the closed side of the drum as it gets hot. As a result, the shoes no longer make contact across the full width of the drum. Quote Link to comment Share on other sites More sharing options...
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