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.
External Pages
1986 Chevrolet Step Van P20, 4.8 T, Automatic, 475/M40 Service Manual /M40 >> Repair and Diagnosis >> External Pages External Pages These are pages that do not belong to the exact selected vehicle (1986 Chevrolet Step Van P20, 4.8 T, Automatic, 400/M40), but are still accessible from a link in your vehicle's manual. Be very cautious using repair info from here because these pages may not apply to your vehicle. Different variant/trim Section 1 (EGR Function Testing - Diesel General Motors) Different car Section 1 (EGR Function Testing) Section 2 (Computer Relearn Procedures) Section 3 (Engine Controls - Specifications - Gasoline) Section 4 (Engine Controls - Specifications - Gasoline) Section 5 (Engine Controls - Specifications - 6.5L Diesel) Section 6 (Engine Controls - Adjustments - Gasoline) Section 7 (Engine Controls - Tests W/O Codes - Gasoline) Section 8 (Engine Controls - Adjustments - Gasoline) Section 9 (Engine Controls - Tests W/O Codes - Gasoline) Section 10 (Engine Controls - Adjustments - 6.5L Diesel) Section 11 (6.5L V8 Diesel & Turbo Diesel - VINS [F,P,S,Y]) Section 12 (Engine Controls - Tests W/Codes - 4.3L) Section 13 (Engine Controls - Theory & Operation - Gasoline) Section 14 (Engine Controls - System/Component Tests - Gasoline) Section 15 (Engine Controls - Tests W/Codes - 5.0L) Section 16 (Engine Controls - Tests W/Codes - 5.7L) Section 17 (Engine Controls - Tests W/Codes - 7.4L) Section 18 (Engine Controls - Basic Testing - Gasoline) Section 19 (Vacuum Diagrams) Section 20 (Engine Controls - System/Component Tests - Gasoline) Section 21 (Engine Controls - Basic Testing - Gasoline) Section 22 (Vacuum Diagrams) Section 23 (Engine Controls - Tests W/Codes - 6.5L Diesel) Section 24 (Engine Controls - Tests W/Codes - 6.5L Diesel) Section 25 (Engine Controls - Tests W/O Codes - 6.5L Diesel) Section 26 (Engine Controls - System/Component Tests - 6.5L Diesel) Section 27 (Engine Controls - Basic Testing - 6.5L Diesel) Section 28 (Engine Controls - Tests W/Codes - Electronic Transmission) Section 29 (Engine Controls - Pin Voltage Charts) Section 30 (Engine Controls - Sensor Operating Range Charts) Section 31 (Engine Controls - Remove/Install/Overhaul) Section 32 (Engine Controls - Remove/Install/Overhaul) Section 33 (Maintenance Information.) Section 34 (Locking Hubs - Automatic) Section 35 (Power Steering Pump) Section 36 (Drive Axle Ratio Identification) Section 37 (Removal & Installation - M/T) Section 38 (Power Steering General Servicing) Section 39 (Power Steering General Servicing) Section 40 (Power Steering General Servicing) Section 41 (Servicing - M/T) Section 42 (Servicing - M/T) Section 43 (Servicing - M/T) Section 44 (Servicing - M/T) Section 45 (Servicing - M/T) Section 46 (Servicing - M/T) Section 47 (Servicing - M/T) Section 48 (Servicing - M/T) Section 49 (Servicing - M/T) Section 50 (Removal & Installation - M/T) Section 51 (Removal & Installation - M/T) Section 52 (Removal & Installation - M/T) Section 53 (Removal & Installation - M/T) Section 54 (Removal & Installation - M/T) Section 55 (Removal & Installation - M/T) Section 56 (Removal & Installation - M/T) Section 57 (Jacking & Hoisting) Section 58 (Feedback Carburetor Tests W/Codes)
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
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.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
No obligation. See pricing before you book.