Why are manual adjustments of automatic slack adjusters considered to be dangerous?
- They can lead to damage in the brake line
- They may give a false sense of security about the effectiveness of the braking system ✓
- They may compromise the axle alignment
- They can result in component wear
Answer: B. They may give a false sense of security about the effectiveness of the braking system
Manual adjustment of automatic slack adjusters is dangerous because it can make you falsely confident that the braking system is working well.
Why this is the answer
Manual adjustment can make you feel the brakes are fixed when they are not. The handbook says an automatic slack adjuster should not need manual adjustment once installed correctly. A manual turn may shorten the stroke for a while, but the automatic slack will reset to its designed stroke. The real problem, such as a fault in the foundation brake, remains. That false confidence is why the handbook calls manual adjustment dangerous. Repeated adjustment can also wear the slack adjuster's internal parts and may lead to early failure, but that is a separate result.
Why the other answers are wrong
- A. They can lead to damage in the brake line — The passage does not say manual adjustment damages the brake line; it points to internal slack adjuster wear and false confidence, not brake line damage.
- C. They may compromise the axle alignment — Axle alignment is not mentioned in the passages as an effect of adjusting automatic slack adjusters.
- D. They can result in component wear — Repeated manual adjustment can wear internal slack adjuster parts, but the handbook gives the misleading sense of brake effectiveness as the reason the practice is dangerous.
Remember it
If an automatic slack adjuster needs a manual turn, treat that as a sign to have the brake system checked, not as a repair.