rebel_horseman said:
An e-brake or "jake brake" is a flap that closes to restrict exhaust flow. The nature of a diesel makes it so that it has little engine braking capability especially when you factor in the turbo adn intercooler. So, manufacturers have a flap that operates in the exhaust stream to retard the engine. Somem work off of oil pressure (like the factory exhaust back pressure valve on the Stroke) and some off of a spring, etc.
They are mainly ideal for towing and that is where they are most notable. I've modified my EBPV so that I can control it as an exhaust brake and unloaded I don't see much help.
This is a good definition of an exhaust brake.... however dont confuse it with the true *Jake Brakes*.
Jake Brakes use solenoids on the exhaust valves themselves and pop them open just as the piston hits TDC on exhaust stroke (they stay closed on the other 3 strokes).... that makes the distinctive sound that Jakes have. It basically turns the engine into a huge air compressor. Intake valves operate normally and the injectors are in a no fuel mode
No pickups with the diesel engines have a Jake Brake. However, exhaust brakes abound all over.
The Jacobs Brake Co. makes an exhaust brake and people throw the name around kinda loosely. Huge difference in braking power between an exhaust brake and a true Jake Brake.
An exhaust brake is just what Rebel said.... a butterfly valve in the exhaust system downstream of the turbo (exhaust manifold on NA engines). No different than shoving a potato up the tailpipe. Most are spring loaded and electric or vacumn controlled. The oil controlled one he mentioned is new to me... never heard of it. But I dont work Internationals much anymore.
Hope that helps ya.