[VAC] Re: Exhaust brakes - A word of caution

[Harvey Barlow]

Title: Re: [VAC] Re: Exhaust brakes - A word of caution

Don,   Current Dodge MOPAR accessory parts catalogs distributed in Dodge truck dealerships offers the Jake Brake and shows a small photograph of the device.  It is a simple butterfly valve in a cast housing which can be installed in the exhaust line downstream of the engine exhaust manifold and turbocharger housing.  When the exhaust brake is closed, exhaust gasses cannot escape and back pressure inside the engine cylinders result.  Earlier 12 valve Cummins engines installed in Dodge Ram pickups had weaker exhaust valve springs which allowed exhaust valves to be forced open when exhaust brakes were installed and applied.  I understand that a lot of problems resulted.  Later 24 valve Cummins engines have been redesigned in various minor ways including stronger exhaust valve springs.  Cummins now offers Jacobs exhaust brakes for sale and installs them on Cummins equipped Dodge trucks.  Dodge does also.  Current engine warranties are not effected by installation and use of Jacobs exhaust brakes on Dodge-Cummins trucks.  This is discussed on the Cummins engine website, http://www.cummins.com   Harvey ----- Original Message ----- From: Don Horn To: Multiple recipients of VACList Sent: Sunday, June 10, 2001 12:02 PM Subject: [VAC] Re: Exhaust brakes - A word of caution I haven’t had any experience using them, but the Jacobs Jake Brake is slightly different from exhaust brakes in that it changes the valve timing, whereas exhaust brakes restrict the flow of the exhaust to apply back pressure.   I believe Jake brakes make a lot more noise in operation than exhaust brakes.   I have ridden on buses equipped with them, and they were set up the same way, i.e. when turned on, releasing the throttle activates the Jake brake.   As I mentioned in my previous post, it’s possible to activate it manually by turning it on or off with your foot off the pedal.  I don’t know how they’re set up in the big rigs. Don From: "Harvey Barlow" <[EMAIL PROTECTED]> Reply-To: [EMAIL PROTECTED] Date: Sun, 10 Jun 2001 10:27:06 -0500 To: Multiple recipients of VACList <[EMAIL PROTECTED]> Subject: [VAC] Re: Exhaust brakes - A word of caution I know that Jacobs, the original "Jake Brake" which has been used on 18 wheelers for 30 years or more is authorized by Cummins, the engine manufacturer for sale and installation on Cummins engines including Cummins powered Dodge Rams by either Cummins shops or Dodge dealers.  I checked and found that a local Dodge dealer can sell it through MOPAR parts and install it in their service department. Has anyone out there had any experience with a Jacobs "Jake Brake"?