Tools You'll Likely Need:
* Wheel chocks: Essential for safety!
* Jack and jack stands: Securely lift the truck. Never work under a vehicle supported only by a jack.
* Lug wrench: To remove the wheels.
* Socket wrench set and ratchet: Various sizes, including metric and standard.
* Hammer and punch (or slide hammer): To help separate parts.
* Torque wrench: Crucial for proper tightening.
* Caliper piston compressor: To retract the caliper pistons.
* C-clamp or similar: Might be needed to compress the caliper.
* Penetrating oil (PB Blaster, etc.): Helps loosen rusted bolts.
* New front brake rotors: Get the correct ones for your truck.
* New wheel bearing grease: If you're repacking the bearings (recommended).
* Appropriate size cotter pin: For the castle nut.
* Safety glasses and gloves: Protect yourself.
Procedure (General Steps):
1. Safety First: Chock the rear wheels, engage the parking brake, and use jack stands to securely lift the front of the truck.
2. Remove the Wheel: Remove the lug nuts and take off the wheel.
3. Remove the Caliper:
* Use the caliper piston compressor to push the caliper pistons back into the caliper. This creates space for the new, thicker rotor.
* Unbolt the caliper from the caliper bracket and carefully hang it out of the way using a bungee cord or wire to avoid damaging the brake line. Don't let the brake line dangle freely.
4. Remove the Rotor: This is where it gets tricky. There are a couple of possibilities:
* Rotor Slides Off: On some 1990 F-150s, the rotor might simply slide off the hub after removing the caliper. Check to see if there are any retaining screws or bolts. If so, remove them first.
* Rotor is Attached to the Hub Assembly: This is more common. The rotor is likely bolted to the hub assembly. You'll need to remove these bolts. Again, penetrating oil beforehand is highly recommended. Once the bolts are out, the rotor will come off the hub.
5. Hub Assembly (If Necessary): If the rotor is integrated with the hub assembly and won't separate easily, you'll probably have to remove the entire assembly. This involves:
* Removing the cotter pin: From the castle nut on the spindle.
* Unscrewing the castle nut: This often requires a significant amount of torque. Use a breaker bar if needed.
* Removing the hub assembly: This can sometimes require a puller to get the hub off. You might need to tap it lightly with a hammer and punch, working your way around the circumference.
6. Inspect the Bearings: When you remove the hub, carefully inspect the wheel bearings. They likely need repacking with new grease if you've taken the hub apart. This is a crucial step to prevent bearing failure and potential damage. Consult a repair manual for proper bearing repacking procedures.
7. Install the New Rotor: Clean the hub mating surface thoroughly before installing the new rotor. Bolt it on securely, using the correct torque specification from your repair manual.
8. Reassemble: Reverse the steps above to reinstall the hub assembly (if removed), the caliper, and the wheel. Ensure the caliper bolts are properly torqued. Make sure the cotter pin is securely installed in the castle nut.
9. Bleed the Brakes: After reassembling everything, bleed the brakes to remove any air that might have entered the system during the process. This is very important for safe braking.
Disclaimer: This is a simplified overview. The actual process can vary depending on your specific truck's configuration and the condition of the parts. Always refer to a repair manual specific to your 1990 F-150 4x4 before attempting this repair. If you're not comfortable performing this task, take it to a qualified mechanic. Working on brakes incorrectly can be dangerous.
