# Drum vs Disc Brakes on Trucks **URL:** \ **Category:** Factual Questions\ **Created:** [March 20, 2009, 4:12am UTC](https://boards.straightdope.com/t/drum-vs-disc-brakes-on-trucks/490122 "2009-03-20T04:12:09Z")\ **Posts on this page:** 7\ **Page:** 2
**Author:** ![bucketybuck](https://avatars.discourse-cdn.com/v4/letter/b/898d66/32.png) [@bucketybuck](https://boards.straightdope.com/u/bucketybuck)\ **Post date:** [March 21, 2009, 3:47pm UTC](https://boards.straightdope.com/t/drum-vs-disc-brakes-on-trucks/490122/21 "2009-03-21T15:47:50Z")
> [@Really\_Not\_All\_That\_Bright](#): > > I would have thought that an employee would be able to type Land Rover correctly. 😕 And I would have thought that no normal person would give a flying fuck. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [March 21, 2009, 4:10pm UTC](https://boards.straightdope.com/t/drum-vs-disc-brakes-on-trucks/490122/22 "2009-03-21T16:10:42Z")
Guess we were wrong. ---
**Author:** ![GreasyJack](https://avatars.discourse-cdn.com/v4/letter/g/df705f/32.png) [@GreasyJack](https://boards.straightdope.com/u/GreasyJack)\ **Post date:** [March 21, 2009, 8:25pm UTC](https://boards.straightdope.com/t/drum-vs-disc-brakes-on-trucks/490122/23 "2009-03-21T20:25:35Z")
> [@Dead\_Cat](#): > > I assume that by this you mean a car with front discs and ABS on those discs, not a car with ABS on drums, because my understanding was that all ABS systems operate with discs, not drums - or am I wrong? You can have ABS with drum brakes and the reason why I mentioned it is that one of the disadvantages of drum brakes is that they’re a lot more prone to locking up than discs, but if it has ABS that’s less of an issue. ---
**Author:** ![FoieGrasIsEvil](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/foiegrasisevil/32/16638_2.png) [@FoieGrasIsEvil](https://boards.straightdope.com/u/FoieGrasIsEvil)\ **Post date:** [March 22, 2009, 12:40am UTC](https://boards.straightdope.com/t/drum-vs-disc-brakes-on-trucks/490122/24 "2009-03-22T00:40:22Z")
> [@GreasyJack](#): > > You can have ABS with drum brakes and the reason why I mentioned it is that one of the disadvantages of drum brakes is that they’re a lot more prone to locking up than discs, but if it has ABS that’s less of an issue. My Scion Xa has front disc/rear drum and ABS. It stops pretty well, although having a 5-speed to transmission brake helps. It probably also helps that the car weighs about 2300lbs. My ABS is REALLY loud and I get a really alarming pedal-thrum when it engages. I suspect it’s because it’s a really cheap little clown car. Gets great mileage, though. I hope a semi truck and I never meet. I doubt I would survive, side airbags or no. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [March 22, 2009, 3:14am UTC](https://boards.straightdope.com/t/drum-vs-disc-brakes-on-trucks/490122/25 "2009-03-22T03:14:15Z")
> [@FoieGrasIsEvil](#): > > My ABS is REALLY loud and I get a really alarming pedal-thrum when it engages. I suspect it’s because it’s a really cheap little clown car. Loud? The ABS shouldn’t make any noise at all. It’s just sensors and an electronic circuit with a servo in the pedal. ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [March 22, 2009, 3:48am UTC](https://boards.straightdope.com/t/drum-vs-disc-brakes-on-trucks/490122/26 "2009-03-22T03:48:19Z")
> [@Really\_Not\_All\_That\_Bright](#): > > Loud? The ABS shouldn’t make any noise at all. Well, it shouldn’t make any noise or do anything noticeable when it’s not engaged, but I’m not aware of any ABS that doesn’t have pedal pulsation and some noise when it’s actually operating. > [@](#): > > It’s just sensors and an electronic circuit with a servo in the pedal. I’m afraid there’s quite a bit more to it than that, most notably a pump and a number of valves. Pretty good description [here](http://auto.howstuffworks.com/auto-parts/brakes/brake-types/anti-lock-brake1.htm). ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [March 22, 2009, 4:04am UTC](https://boards.straightdope.com/t/drum-vs-disc-brakes-on-trucks/490122/27 "2009-03-22T04:04:39Z")
> [@Really\_Not\_All\_That\_Bright](#): > > Loud? The ABS shouldn’t make any noise at all. It’s just sensors and an electronic circuit with a servo in the pedal. On many ABS systems the hydraulic pump is really loud. You have to move brake fluid against a couple of thousand pounds of pressure. That takes a good sized and often quite loud electric motor and pump. [Previous page](https://boards.straightdope.com/t/drum-vs-disc-brakes-on-trucks/490122.md?page=1)