1988 Chevrolet Hi-Cube 5.7 M, 475/M40FACTORY OEM SERVICE PROCEDURE

PCV System: Maintenance: Notes

As engine may idle slow or rough due to clogged ventilator valve or system, never adjust carburetor idle without first checking valve and system. If ventilator valve or system become clogged, all crankcase ventilation will stop and could result in serious engine damage.

It is recommended the crankcase ventilation system be checked more frequently if vehicle is operated under severe conditions (extreme dust, prolonged idling, trailer hauling or short trips in cold weather).

Factory Service Tools

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:

  • 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.