What could be necessary to maintain adjustment in automatic brake adjusters?
- Regular oiling and maintenance.
- Making a number of full brake applications. ✓
- Removing and reinstalling the slack adjusters.
- Changing the brake fluid.
Answer: B. Making a number of full brake applications.
Making a number of full brake applications can be necessary to maintain adjustment in automatic brake adjusters.
Why this is the answer
The handbook says automatic slack adjusters reset themselves as you make ordinary brake applications while driving. That is how they keep brake stroke in adjustment, so the answer points to making full applications. The same section says these adjusters still need to be checked during a pre-trip inspection, and that manual adjustment is not the way to maintain them. It does not say that oiling, removing, or changing fluid keeps them adjusted.
Why the other answers are wrong
- A. Regular oiling and maintenance. — Regular oiling and maintenance is not described as the way automatic slack adjusters keep their adjustment; the handbook calls for checks at service intervals, not oiling as the adjustment method.
- C. Removing and reinstalling the slack adjusters. — Removing and reinstalling the slack adjusters is not needed to maintain adjustment; the handbook says once properly installed they should not need manual adjustment.
- D. Changing the brake fluid. — Changing the brake fluid is not part of this; these are air brakes, and the passages discuss air pressure and pushrod stroke, not brake fluid.
Remember it
Think of it this way: normal driving brake applications are what let automatic slack adjusters do their self-adjusting job; checking stroke is still a separate pre-trip task.