Bullnose Bill Answer
by Ed

What maintenance tasks should I perform on my 1986 Ford F250 7.5 4×4?

Bullnose Bill explains maintenance tips for a 1986 Ford F250 7.5 4x4.

This Q&A session is powered by Bullnose Bill, Bullnose Garage’s advanced AI mechanic.
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Bill says:

Keeping your 1986 F250 with the 7.5L V8 running smoothly involves regular maintenance. Here’s a solid checklist to follow:

Engine Maintenance

  1. Oil and Filter Change

    • Change every 3,000 miles or every six months.
    • Use a quality oil filter and the recommended oil grade (typically 10W-30).

  2. Air Filter Replacement

    • Check every 12,000 miles and replace if dirty.
    • Consider a high-flow aftermarket option for better performance.

  3. Fuel System

    • Replace the fuel filter every 24,000 miles.
    • Consider a fuel system cleaner to keep injectors clean.

  4. Cooling System

    • Inspect the radiator, hoses, and water pump for leaks.
    • Flush and replace coolant every 2 years.

Ignition System

  • Spark Plugs and Wires

    • Replace spark plugs every 30,000 miles.
    • Inspect and replace wires if they’re cracked or worn.

  • Distributor Cap and Rotor

    • Check for wear and replace if necessary.

Transmission and Drivetrain

  1. Transmission Fluid and Filter

    • Change every 30,000 miles.
    • Make sure to use the correct type of ATF for your transmission.

  2. Transfer Case Fluid

    • Change fluid every 30,000 miles for 4×4 systems.

  3. Differential Fluid

    • Inspect and replace every 60,000 miles.

Brakes and Suspension

  1. Brake System

    • Check pads, rotors, and lines every 10,000 miles.
    • Bleed the brake system every 2 years to replace fluid.

  2. Suspension and Steering

    • Inspect bushings, ball joints, and tie rods for wear.
    • Lubricate steering components regularly.

Tires and Alignment

  • Tire Rotation

    • Rotate tires every 6,000-8,000 miles to ensure even wear.

  • Alignment Check

    • Get the alignment checked yearly, or if you notice uneven tire wear.

General Tips

  • Battery and Electrical System

    • Clean battery terminals and check charge.
    • Inspect all lights and replace any burnt-out bulbs.

  • Exhaust System

    • Inspect for leaks or damage periodically.

  • Rust Prevention

    • Keep an eye on rust, especially on the frame and body panels.
    • Treat any spots promptly to prevent spread.

Regular maintenance keeps these classics running great. If you’re ever unsure about a procedure, there may be a related video on the Bullnose Garage channel — worth a look. Happy wrenching!

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User:

What is the first modification I should consider for my F250?

Bill avatar

Bill:

When it comes to your first mod for a 1986 F250, it largely depends on what you’re looking to achieve—performance, comfort, or aesthetics. Here are some popular first mods:

Performance

  • Exhaust Upgrade

    • A performance exhaust can improve airflow and add a nice growl to your truck.

  • Air Intake System

    • A high-flow air intake can help your engine breathe better, which might give you a slight performance boost.

Comfort

  • Seat Upgrade
    • Swapping in more comfortable seats can make a big difference if you spend a lot of time driving.

Aesthetics

  • LED Lighting
    • Upgrading to LED headlights and interior lights can improve visibility and give your truck a modern look.

Versatility

  • Toolbox or Bed Cover
    • Useful for securing your gear and tools, and it adds a practical touch to your truck.

Think about what matters most to you and start there. If performance is key, going with an exhaust or intake is a solid choice. For comfort or practicality, seats or bed accessories are great. Enjoy modding your Bullnose!

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User:

What could cause my F250 to crank but not start?

Bill avatar

Bill:

If your truck cranks but won’t start, it usually boils down to one of three main issues: fuel, spark, or air. Here’s how to troubleshoot each:

1. Fuel System

  • Fuel Pump

    • Listen for a humming sound from the fuel tank when you turn the key to the "ON" position. If it’s silent, the pump might be failing.

  • Fuel Filter

    • A clogged filter can restrict flow. If it hasn’t been changed in a while, it’s a good place to start.

  • Fuel Pressure

    • Test the fuel pressure with a gauge. It should meet the specifications for the 7.5L engine.

2. Ignition System

  • Spark Plugs

    • Remove a plug and check for spark. If there’s no spark, inspect the plugs, wires, and distributor.

  • Ignition Coil

    • A bad coil can prevent spark. Test it with a multimeter.

  • Distributor Cap and Rotor

    • Remove and inspect for cracks or carbon tracking.

3. Air System

  • Air Filter

    • Ensure it’s not clogged and that air can flow freely into the engine.

  • Mass Air Flow Sensor (MAF) or Throttle Position Sensor (TPS)

    • Check for any fault codes that might indicate a sensor issue.

Other Considerations

  • Battery and Charging System

    • Ensure the battery is fully charged and all connections are clean and tight.

  • Engine Timing

    • If the timing chain or belt has slipped, it can cause these symptoms.

Troubleshooting Tips

  • Start with the basics: check for codes with a diagnostic tool.
  • Listen for unusual sounds when cranking, as they might give clues.
  • If you’re stuck, there might be a related video on the Bullnose Garage channel that can help.

If none of these pan out, it might be worth digging deeper into each system or consulting a professional. Good luck!

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User:

Are 315/75/16 tires compatible with my 1986 F250?

Bill avatar

Bill:

Fitting 315/75/16 tires on your 1986 F250 can be challenging without modifications. Here’s what to consider:

Fitment Considerations

  1. Lift Kit

    • You’ll likely need a lift to accommodate the larger tires. A 4-inch suspension lift is a common choice for this size.

  2. Wheel Backspacing

    • Ensure the wheels have the correct backspacing to avoid rubbing on the suspension or body.

  3. Trimming

    • You might need to trim fenders or modify wheel wells to prevent rubbing during turns or suspension compression.

  4. Gear Ratios

    • Larger tires can affect performance and fuel economy. Consider re-gearing the differentials to match the new tire size.

Checking Fitment

  • Test fit one tire before committing to the set.
  • Remember, off-road use can increase the likelihood of rubbing.

These mods involve some investment, so consider your driving needs and budget. If you’re looking to tackle this mod, there might be helpful guides or videos on Bullnose Garage to walk you through it.

This answer was written by Bullnose Bill, our AI shophand trained on hundreds of Bullnose-era Ford topics. He knows his way around old Ford Trucks.

As with all of Bill’s answers, it has been reviewed and approved by Ed Zenisek, the man behind Bullnose Garage and a real human being.

While we do our best to keep things accurate, always double-check any repair advice and use proper safety procedures. For real-world walkthroughs and more hands-on content, check out Bullnose Garage on YouTube or visit the BullnoseFord SubReddit.

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