Jake Brake / Pac brake question

My Dynasty had an exhaust brake. Changed the factory one out to the PacBrake PRXB. World of difference. Much better braking power. The Executive has a two stage engine brake. Better holding power than the PacBrake.

A Jake Brake modifies the timing on the exhaust valves so that, when braking is needed, the exhaust valves open right as the piston reaches the top of the compression stroke. The energy gathered in the compressed air is released, so the compression stroke actually provides the braking power. Low position opens three valves, High position opens all six.

As for telling from the cockpit; generally speaking, an exhaust brake will simply have an on/off switch on the console. An engine brake will have a 2 or 3 position switch in a similar place. Some models also have a floor mounted pedal to activate either one. Most higher end Monacos do. Hope this helps...Dennis

I have an 05 Fleetwood DP with exhaust brake. It works just fine in the mountains; rarely have to use the foot brake BUT its a 30,000 pound RV not a 40,000 pound 44 footer.

Most entry level DPs are going to have exhaust brakes. Few have retarders; most if not all Foretravels do. They do raise the trans temp a little.

The only brake that I'm familiar with is a Jake Brake, I've driven tractor trailers all my working life. There will be a switch on your dashboard panel saying Jake Brake. I've seen them come in 1,2 and 3 speeds. FYI, what basically a Jake Brake does is shuts the valves off in the diesel engine heads, and turns the motor into a compressor creating back pressure that slows the vehicle down.

Ask the salesman what type brake. Test his knowledge right away. A good salesman knows his vehicles for sale and if he hems and haws you know you probably have an amateur.

I think the options, in order of effectiveness, are retarder, engine brake and exhaust brake. There are some differences in operations between brands. I have a PAC brake and it's fine for most applications. I drove a Foretravel with retarder and that is about a thousand percent better than my PAC brake. It's also adjustable on the fly so you can determine how much braking you want.

I'm not sure you can tell 100 percent what type of aux brake a coach has by looking at the cockpit. You can tell if the coach has a retarder (very few do) because it will have a lever on the side panel to adjust the braking effectiveness. A PAC brake will generally have a floor switch to the left of the steering wheel. Your best bet is probably to look at the build sheet for the coach.