MST MST Steering & Control Systems 1 — Questions and Answers
Question 1: What is the primary cause of excessive steering wheel play in a rack-and-pinion hydraulic steering system?
- Worn or damaged steering cable or low hydraulic fluid level (Correct answer)
- Too much engine tilt angle
- Corroded trim tabs
- A seized throttle cable
Correct answer: Worn or damaged steering cable or low hydraulic fluid level
Excessive play in hydraulic steering is most commonly caused by low fluid level, air in the system, or a worn pump — mechanical play is rare in hydraulic systems.
Question 2: When bleeding a hydraulic steering system, what is the correct procedure?
- Turn the helm lock-to-lock multiple times while adding fluid at the reservoir until no air bubbles appear (Correct answer)
- Run the engine at full throttle to build pressure
- Remove the cylinder bleeder screw and fill from the cylinder
- Add fluid only when the engine is running at idle
Correct answer: Turn the helm lock-to-lock multiple times while adding fluid at the reservoir until no air bubbles appear
Cycling the helm lock-to-lock while topping off the reservoir forces air out of the system and allows fluid to fill all passages.
Question 3: What type of cable is used in most mechanical single-station outboard steering systems?
- Push-pull rotary steering cable (Correct answer)
- Stainless wire rope
- Bowden cable
- Rigid rod linkage
Correct answer: Push-pull rotary steering cable
Push-pull rotary cables transmit both push and pull forces through a flexible conduit, allowing steering force to be directed around bends to the outboard.
Question 4: What ABYC standard covers steering system installations on recreational boats?
- ABYC P-17 (Correct answer)
- ABYC H-24
- ABYC E-11
- ABYC A-3
Correct answer: ABYC P-17
ABYC P-17 (Mechanical and Non-Mechanical Steering Systems) establishes design and installation requirements for recreational boat steering.
Question 5: A twin-engine boat with hydraulic steering pulls strongly to one side at rest but steers normally under power. The most likely cause is:
- Unequal engine trim angle between the two engines (Correct answer)
- Low hydraulic fluid in the port side cylinder
- A seized port engine throttle cable
- Worn steering wheel hub
Correct answer: Unequal engine trim angle between the two engines
Unequal trim angles cause an asymmetric thrust vector at rest that corrects under power as hydrodynamic forces equalize.
Question 6: What is the purpose of the tilt tube on an outboard engine steering system?
- To provide a pivot point for the steering cable attachment to the outboard's swivel bracket (Correct answer)
- To allow the engine to tilt up for shallow water
- To house the trim motor wiring
- To attach the engine to the transom
Correct answer: To provide a pivot point for the steering cable attachment to the outboard's swivel bracket
The tilt tube is a horizontal tube through the swivel bracket that the steering cable end cap threads into, providing the pivot for left-right steering movement.
MST MST Steering & Control Systems 1
What is the primary cause of excessive steering wheel play in a rack-and-pinion hydraulic steering system?