Downhills!

Rule of thumb is to descend the hill in the same gear you used pulling up the hill.

Doesn't always work this way. For one reason, trucks pull alot better now than when they did when this rule of thumb was devised.

Also it depends on the transmission in the truck. If the truck has a ten speed, then 5th or 6th. Depending on the speed limit for trucks on the hill. The jake should hold the load back nicely either way.

Being completely dependent on the jake brake is not a good idea because it can stop working at the worst possible time so don't forget how to descend the hill using foot brakes only.

 

in my opinion it is two hard to say. every mountain grade is different and then considering weather and traffic amongst other things. like mt. eagle in tennessee, i'll come down at about 50-55 mph w/ jake on and on occassionss will hit brakes to slow it down when it goes over 60-65. and that there is , if i can remember right, a 7% downgrade, or is it 6.

 

To answer your question, just don't over rev the engine, usually 2100. All the jakes I driven will get stronger as the rpm increases but you can over rev the engine.

 

From the CDL book as I am studdying it tonight
1. Select 1 gear lower at least then what it took you to climb the hill.
2. When going down the hill if your ideal speed is 40 mph apply the brakes with light steady pressure to get the truck to slow to 35 mph and then when the speed reaches 40 mph repeat the same steps over. Don't pump the brakes as you will lose air pressure.

 

No problem on those downhills...just put it in the high hole, wind it out to the governor and then knock it out of gear. If you lose your nerve, that's what the runaway truck ramps are for!

 

Don't listen to the Penguin. Why you ask? Well he's a Penguin for God's sake, who would take advise from a bird that can't even fly.