1987 Honda Prelude Base, AutomaticFACTORY OEM SERVICE PROCEDURE

Constant Vacuum Generator

  1. Disconnect hose No. 33 from frequency solenoid valve B and connect vacuum gauge. Start engine and allow to run at idle. After vacuum stabilizes, reading should be 6-11 in. Hg vacuum.
  2. If vacuum stabilizes within range, constant vacuum generator is okay. Reconnect hose to frequency valve B. If vacuum stabilizes above or below specified range, replace constant vacuum generator.
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:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.

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