Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Speed Control Systems - Automatic: Description
System uses manifold vacuum to power a throttle servo unit. When speed adjustment is necessary, servo moves the throttle by receiving a varying amount of controlled vacuum from transducer. Speedometer cable from transmission drives transducer and a cable from transducer drives instrument panel speedometer. There are 2 control switches operating speed control. The first is a "CRUISE" slide switch with "OFF", "ON", and "RESUME" positions. The second is a "SET-COAST" button switch located on end of turn signal lever. It controls engagement of transducer. Two brake release switches are provided. An electric switch disengages transducer and a vacuum valve (switch) decreases vacuum in servo unit to quickly return throttle to idle position when brake pedal or clutch is depressed.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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