Braking/OverDrive Options when dealing with steep incline/decline

[Gary RV_Wizard]

For A and his diesel:
Tow/Haul is a transmission feature typically included with gas engine power trains. Diesels don't have inherent engine braking like a gas engine (they free-wheel on downgrades), so they are often equipped with either an internal engine brake (aka "Jake brake") or an exhaust brake. That 5.9L Cummins you have doesn't get an engine brake, but may have an exhaust brake. If you do, it will nicely handle downhill braking. If not, it's strictly use of the service brakes cause downshifting is ineffective.

 

[Larry N.]

Same engine on almost all Cruise America RVs.

Cruise America doesn't have diesels. See Gary's comment above about diesels and tow/haul being useless.

 

[Kirk]

If not, it's strictly use of the service brakes cause downshifting is ineffective.

I must disagree a little as I drive a diesel truck with no engine or exhaust braking. I will agree that the engine braking is of very limited effect but one should still shift to a lower gear and take advantage of what additional resistance that gives. You will need to use braking and you should go down steep grades more slowly than would need be if you did have an exhaust brake. You will also need to be very careful about over use of the brakes. If you go to a low enough gear you will only need to apply brakes as the engine RPM gets too high and then brake sharply to slow back down to well below the limit and then allow it to slowly rise again. If you find that you are in too high a gear, brake down hard to a slow enough speed to downshift to a lower gear. Better to come down too slowly than too fast.