# What are "Jake brakes?" **URL:** \ **Category:** Factual Questions\ **Created:** [May 7, 2001, 10:29pm UTC](https://boards.straightdope.com/t/what-are-jake-brakes/64691 "2001-05-07T22:29:38Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![aha](https://avatars.discourse-cdn.com/v4/letter/a/eada6e/32.png) [@aha](https://boards.straightdope.com/u/aha)\ **Post date:** [May 7, 2001, 10:29pm UTC](https://boards.straightdope.com/t/what-are-jake-brakes/64691/1 "2001-05-07T22:29:38Z")
I saw a sign in a small town the other day that said, “Jake Brakes are illegal in this town.” I must admit I am not sure what they are. Must have something to with sound and trucks. Anyone? ---
**Author:** ![Odieman](https://avatars.discourse-cdn.com/v4/letter/o/a87d85/32.png) [@Odieman](https://boards.straightdope.com/u/Odieman)\ **Post date:** [May 7, 2001, 10:43pm UTC](https://boards.straightdope.com/t/what-are-jake-brakes/64691/2 "2001-05-07T22:43:28Z")
I did a quick search of the archives and came up with this aha. [http://www.straightdope.com/mailbag/mjake.html](http://www.straightdope.com/mailbag/mjake.html) I hope that answers your question: Keith ---
**Author:** ![screech-owl](https://avatars.discourse-cdn.com/v4/letter/s/82dd89/32.png) [@screech-owl](https://boards.straightdope.com/u/screech-owl)\ **Post date:** [May 7, 2001, 10:47pm UTC](https://boards.straightdope.com/t/what-are-jake-brakes/64691/3 "2001-05-07T22:47:48Z")
It’s a really loud way of slowing/stopping a truck. [GQ answer](http://boards.straightdope.com/sdmb/showthread.php?threadid=64642) To quote from Stephen’s post: “Yup. It pretty much indicates a neighborhood that got tired of hearing BBDDBBDDbdbdbddbdbdbdbddbbbddbdbbdbdbb bdddbdbdbddbd bdbbdbddbdb at all hours.” [Mailbag answer](http://www.straightdope.com/mailbag/mjake.html) I’ll attest, they’re really loud inside the truck too, having ridden with (former)Roommate on some of his trucking deliveries and driving carnival rides. ---
**Author:** ![JillGat](https://avatars.discourse-cdn.com/v4/letter/j/9fc29f/32.png) [@JillGat](https://boards.straightdope.com/u/JillGat)\ **Post date:** [May 8, 2001, 3:32am UTC](https://boards.straightdope.com/t/what-are-jake-brakes/64691/4 "2001-05-08T03:32:27Z")
I am crushed, aha. ---
**Author:** ![Mikahw](https://avatars.discourse-cdn.com/v4/letter/m/e9bcb4/32.png) [@Mikahw](https://boards.straightdope.com/u/Mikahw)\ **Post date:** [May 8, 2001, 3:57am UTC](https://boards.straightdope.com/t/what-are-jake-brakes/64691/5 "2001-05-08T03:57:57Z")
Around here, the signs say “unmuffled compression brakes prohibited” instead of “no jake brakes”. I bet that makes Jacobs Vehicle Systems a bit happier. I’ve never ever heard a loud compression brake. That means either 1 of 2 things: 1)muffled compression brakes really aren’t that loud 2)I mistook another sound for a compression brake 3)no, I won’t do it. I really won’t Not this time, buddy I believe that the answer was #1, but it could have been #2. Anyways… ---
**Author:** ![pesch](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pesch/32/4925_2.png) [@pesch](https://boards.straightdope.com/u/pesch)\ **Post date:** [May 8, 2001, 4:37am UTC](https://boards.straightdope.com/t/what-are-jake-brakes/64691/6 "2001-05-08T04:37:18Z")
Jacobs Vehicles Systems have been threatening to sue the !#$%%@ out of municipalities and states that use Jake’s Brakes on their signs. They’re claiming trademark infringement. Of course, JB’s is the common term for it outside the lawyer’s offices, no matter what Jacobs thinks. They’re going through this now in the Gettysburg area. ---
**Author:** ![aha](https://avatars.discourse-cdn.com/v4/letter/a/eada6e/32.png) [@aha](https://boards.straightdope.com/u/aha)\ **Post date:** [May 8, 2001, 12:46pm UTC](https://boards.straightdope.com/t/what-are-jake-brakes/64691/7 "2001-05-08T12:46:31Z")
> [@](#): > > \*Originally posted by JillGat \* > \*\*I am crushed, aha. \*\* Why are you crushed Jill? What am I missing here? ---
**Author:** ![screech-owl](https://avatars.discourse-cdn.com/v4/letter/s/82dd89/32.png) [@screech-owl](https://boards.straightdope.com/u/screech-owl)\ **Post date:** [May 8, 2001, 1:08pm UTC](https://boards.straightdope.com/t/what-are-jake-brakes/64691/8 "2001-05-08T13:08:05Z")
> [@](#): > > \*Originally posted by aha \* > **Why are you crushed Jill? What am I missing here?** You missed her Staff Report in the archives.