No jakes, how to slow down on hills?

The idea behind the jakes and engine brakes was to reduce wear and tear on the wheel brakes, with no jakes you'll have no choice but to use your brakes, however what I used to do if it was not a really steep decline, would just use the trailer brakes only that way you save the prime movers brakes or I would alternate between the two options. The other option but will be really slow and if its not a huge down grade is not really worth it, is put the truck in a gear that will hold it on the decline then you won't have to use the brakes at all.

 

On off method as well as riding them with 10psi or less both work as long as u are in the correct gear. The gear u want to be in is where u are slowing down when applying light pressure on the breaks. Any higher gear then that u will burn them up

 

You can use almost any method in the East or when your non-jake vehicle weight isn't maxed out without smoking your brakes. Letting your speed build and then slowing it back down is like cutting a hole in your sinking boat to let the water out. It is like borrowing a thousand more dollars on your credit card at 25% to get the extra 2% cash back. It's self-defeating. You, or your brakes, have to deal with not just a little more energy, but lot's more energy.

The energy you generate from increased speed is FAR more than if you keep your speed steady. In the examples below notice how the faster you go the wider the difference is in the percentage change in speed and energy.

Truck 80,000 lbs, speed 55 mph
Ex 1. 80,000 lbs Truck Speed 55 mph constant downhill
Ex 2. 80,000 lbs Truck Speed 60 mph or +8% / Energy +19%
Ex 3. 80,000 lbs Truck Speed 65 mph or +18% / Energy +39.6%
Ex 4. 80,000 lbs Truck Speed 70 mph +27% / Energy +61.9%
A little speed increase has a HUGE heat effect on the brakes.
Kinetic Energy Calculator

Example 1) An 80,000 lbs truck doing 55 mph has 10,968,415 units of energy (Joules)
Example 2) An 80,000 lbs truck doing 60 mph has 13,053,320 units of energy (Joules)
***********speed increased 5 mph or 8.3%, but your energy increased 19%
Example 3) An 80,000 lbs truck doing 65 mph has 15,319,522 units of energy (Joules)
***********speed increased 10 mph or 18%, but your energy increased 39.6%
Example 4) An 80,000 lbs truck doing 70 mph has 17,767,019 units of energy (Joules)
***********speed increased 15 mph or 27%, but your energy increased 61.9%

 

Lower gear than what you climbed in. Take it slow and use the lower gear to slow the engine speed. Steady brake pressure. You don't want to be braking to hard or you'll burn them up.

 

If you are in the lowest gear possible at the slowest speed possible beginning at the top of the hill any braking method will work just fine without jakes. It's the speed that creates the heat issues.

 

Fan and a/c on, winter or not, gains maybe half a gear.

 

Sounds about right. According to two dyno runs my truck lost close to 65 hp with the fan on compared to when it was off. Same truck. Same dyno. Different operator.

 

Never had a truck without jakes.
As an experiment while stopped on the steepest part of the Coquihalla (11%) for an accident road closure and having 102,000 lbs gross weight. When the road slowly opened, I found the first 2 or three gears held the truck back just fine and it would even slow down, around 4th gear it started to pickup speed on its own.