Keithb,
By the way, if you do have a foot pedal it works just like your service brake pedal, e.g., when you press it the Jake brake is on and when you release it the Jake brake is off.
On the other hand, if do NOT have a floor pedal then you have an on/off switch PLUS a Hi/Lo switch. In this case when the on/off switch is ON every time you let your foot off the accelerator pedal the Jake brake is turned on and is slowing you down. This means if you do not want to slow down as fast as the Jake brake is slowing you, you must again press the accelerator pedal to stop the Jake brake or you must turn the Jake brake off with the on/off switch which requires constantly looking (eyes off road) and finding the on/off switch to keep moving it between on and off. We did not like this especially in traffic and on down hill runs.
We have had both an on/off switch and a floor pedal. We settled on a floor switch so now we just leave our Jake brake on the HI position. We never have to look for a Hi/Lo or an On/Off switch so we can keep our eyes on the road. Because we now have a floor pedal (no on/off switch) here is what we do. When we are driving and want to stop accelerating, slow, or stop the coach we let off the accelerator pedal. This lets the diesel engine slow up the coach a very LITTLE bit (almost like coasting in a car). If we want to slow faster we press the Jake brake floor switch to slow the coach at a faster rate. And last, we press the service brake to stop or slow down at a much faster rate.
If you have never used a Jake or Pac Brake pedal it DOES NOT require foot pressure like the service brake pedal. It is a small flat box or circular pedal that is hinged at the top (upper portion) of the pedal. By doing it this way you really do not have to press the pedal. You just set the ball of your foot on the rear (bottom) of the pedal and the Jake brake goes on. It DOES NOT require pushing pressure like a brake pedal does. It almost like setting the weight of your foot on the pedal.
Going down mountains it's great because at the top of a hill we press the floor switch. Then when there are less steep or flat spots on the long downhill run and the Jake brake is slowing you to much we just let off the pedal and again press the pedal when the incline gets steeper. When we did not have a floor pedal we had to look over, find, and press the off switch and when the hill got steeper again we had to look for and press the ON switch again (imagine doing that in bumper to bumper traffic). Or, on the other hand, instead of turning it the Jake brake OFF/ON we could have pressed the accelerator pedal to turn the Jake brake OFF but that meant if we pressed it a litle too much the engine started increasing the coaches speed which went against our instincts on a long downhill run where our objective was to control the downhill speed of the coach. We weigh 44,000 lbs with our tow car and we do have brakes in the tow car.
Also, in stop and go city traffic we disliked the fact that every time we took our foot off the accelerator the Jake brake started slowing us. In traffic we perfer the ability to coast (no power on), press the pedal to use the Jake brake, or use the service brake like we do in our car. For example, in our car we press the gas pedal to go, let off the gas pedal to coast, sometimes downshift to slow the car at a faster rate if we want to (this is similar to the Jake brake in a MH), and press the brake pedal to stop.
Our Jake brake is set to automatically downshift all the way down to 2nd gear. We like this because approximately 25% of the time we do not press the service brake pedal until the coach is going only 15 MPH. 15 MPH is the magic number because that is were the Jake brake turns off, that is, if it's set to downshift all the way down to second gear. Sometime when you have the road to yourself press the downshift button (down arrow) on your Allison transmission so the target gear is 1st gear and you'll see that the Jake brake will work all the way down to about 7-1/2 MPH before you feel that slight pulse of it release and you're coasting.
JerryF
