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.
1978 Mazda Cosmo Automatic TransFACTORY OEM SERVICE PROCEDURE
1978-79 RX7 (Man. Trans.)
- Disconnect vacuum sensing tubes from vacuum control valve and vacuum pipe. Disconnect vacuum control valve. Blow through vacuum sensing tube. Air should pass through valve and come out the side fitting (vacuum pipe).
- Apply battery power to vacuum control valve at one valve electrical terminal and ground the other. See Fig 1. Again, blow through vacuum sensing tube. Air should come out of air filter. If valve does not respond in this manner, replace it.
Factory Service Tools
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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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