Companies usually disconnect the jake brake because new drivers are not effecient at shifting and if done improperly could tear up a transmission. Until a driver learns or becomes more effecient in shifting it is better this way. THere is no safety jeapordized. There are many trucks on the road with out jake brakes! If a driver executes braking and down shifting and is in the proper gear to proceed down a hil, thet will heat up but not to extreme.
FYI: a truck should proceed down the hill in the samre gear it take to climb the hill |