Q
I was taught to drive a car with a manual transmission and to disengage the clutch BEFORE braking. Since a manual transmission has a MECHANICAL link to the engine, how is it possible to brake while the clutch is engaged on a BIG RIG without stalling? This is confusing me.
A
You can, and indeed you MUST, brake while the clutch is engaged. The only time that you will have the clutch depressed is between gears as you shift up or down or when you are at a complete stop waiting to start moving again. The trick is that you must keep the engine's rpms in the "operating range" (usually from 1000 rpms to 1700 rpms) by constantly downshifting as you slow to a stop. Once downshifting slows you down, and just before you come to a stop, depress the clutch fully and apply more pressure on the brakes and slow to a stop.
In an automobile, you are dealing with a lot less weight than a truck and it's no real chore for the brakes to slow or stop the lighter car without using the drive train to help slow the vehicle down. While you should be downshifting and slowing the car down using the whole drive train, most people are not actually trained to properly drive standard transmissions and they usually take their tests for a regular driver's license in a car equipped with an automatic transmission. Anytime the car or truck is in motion and you have the clutch to the floor it's called "coasting out of gear." It's very common and it's one of the "bad car habits" that will drive an instructor to yank what's left of his hair out by the roots!
There is about a four second rule when using the clutch. If you are moving down the road or approaching an intersection, you have about a four second period of time to be on the clutch before the examiner will start taking notice and possibly taking off points (or adding them) from your score.