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.
Combination Air By-Pass/Air Control Valve
The combination air by-pass/air control valve is used with some MTA systems. The valve combines functions of 2 normally closed valves in one unit. There are bleed type and non-bleed type valves. Both look alike. Bleed type valves will have percentage of bleed rating molded on side of case. The by-pass portion of valve releases air into atmosphere, while control valve portion redirects air.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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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