Clutch

I was told by a friend that his instructor at a Trucking School can be sitting on a Hill ,(Going upwards) in a semi ,and hold the truck in place without touching the brakes ,with just only his clutch . I find this very hard to believe, because when I'm on a hill, I sometimes roll backwards when applying brakes ,and clutch. Can someone please enlighten me on this . I know I'm a recent graduate, but I find this hard to believe

Totally possible. I can't imagine it's good for the drivetrain though.

Depends.on the steepness of the hill. If it's slight, just let the clutch out til it starts to grab, then release brake and accelerate.

If it's a steep hill, use the trailer brake to hold the truck while you let out on the clutch and apply throttle.

But as Paul said, I wouldn't do it, it's not good for the drivetrain

Very possible and not hard to do. But like others said, its hard on the clutch and they're expensive and a pain to replace.

If you couldn't use the clutch to hold a truck in place on a hill, how would you ever get going from a dead stop on a hill? You have to be able to get the truck rolling uphill from a dead stop so it stands to reason you could hold it in place if you wanted to. Otherwise, once a truck stopped on a hill you would have to either roll backwards down to the bottom to start over or park it there permanently.

And never use the throttle and clutch at the same time the way you do in a four wheeler. If you can't get the truck rolling by using the clutch only then you're in too high of a gear. Trucks are geared to get rolling under any circumstances, including from a dead stop with a full load facing up a hill. Put it in the lowest gear necessary to be able to let out the clutch smoothly until it's fully out and you're rolling forward without touching the throttle in the process.

I was told by a friend that his instructor at a Trucking School can be sitting on a hill ,(Going uphill) in a semi ,and hold the truck in place without touching the brakes ,with just only his clutch . I find this very hard to believe, because when I'm on a hill, I sometimes roll backwards when applying brakes ,and clutch. Can someone please enlighten me on this . I know I'm a recent graduate, but I find this hard to believe

Allowing the clutch to slip for any length of time will wear it out quickly. Slipping the clutch while you wait for a green light is bad. Slipping the clutch as you get started from a stop is OK.

Here's a little known (I guess) fact: there is about a one second gap after you let off air brakes until the wheels are able to roll. Once you get your foot coordination down between clutch and accelerator, you can use that little bit of help in starting up your San Francisco hill.