Tools You'll Need:
* Wrench(es): The correct size(s) to fit the line fittings. These are usually flare nut wrenches to avoid rounding the nuts.
* Socket(s) and ratchet: May be necessary depending on the accessibility of the fittings.
* Basin or container: To catch the hydraulic fluid. Brake fluid is hazardous, so use appropriate safety measures (gloves, eye protection).
* Shop rags or paper towels: For cleaning up spills.
* New crush washers: These are crucial for preventing leaks. Get replacements before starting.
* Penetrating oil (PB Blaster, etc.): To help loosen corroded fittings.
* Jack and jack stands (highly recommended): For safe and easier access to the area.
Procedure:
1. Safety First: Disconnect the negative battery cable to prevent accidental short circuits. Jack up the truck and securely support it on jack stands. Never work under a vehicle supported only by a jack.
2. Locate the Hydraulic Line: The clutch hydraulic line runs from the master cylinder (usually located near the brake master cylinder) to the slave cylinder (mounted on the transmission). Identify the line's connection points.
3. Prepare for Fluid Drainage: Place your container under the fitting you'll be disconnecting first. This minimizes fluid spillage.
4. Disconnect the Line: Apply penetrating oil to the fittings several hours (or overnight) before you start this step. Use the correct wrench(es) to carefully loosen and remove the fitting(s) at the master cylinder end *first*. These will likely be flare nuts. Turn the fitting slowly and steadily to avoid stripping the threads. As you loosen, the fluid will begin to drain.
5. Disconnect the Slave Cylinder End (if necessary): Once the master cylinder end is disconnected, you'll then disconnect at the slave cylinder. This may be more difficult to access depending on your truck's configuration. Again, use penetrating oil and proceed slowly and carefully.
6. Remove the Line: Carefully remove the hydraulic line from its routing. Take note of its routing to ensure correct reinstallation.
7. Clean Up: Wipe up any spilled fluid and clean the fitting areas with a clean rag.
8. Installation (Reverse Order): When installing the new line (if replacing) or re-installing the existing line, follow these steps in reverse order. Use new crush washers on both fittings to ensure a leak-free seal. Tighten the fittings snugly, but avoid over-tightening.
9. Bleed the Clutch System: Once the line is reconnected, you MUST bleed the clutch hydraulic system to remove air bubbles. This process involves opening the bleed valve on the slave cylinder while an assistant depresses and holds the clutch pedal. Consult your repair manual for the proper bleeding procedure.
Important Considerations:
* Corrosion: Older vehicles often have corroded fittings. Use penetrating oil liberally and be prepared for the possibility of broken fittings. If a fitting breaks, you may need to replace the entire line or section of the line.
* Fluid Type: Use only the correct type of clutch hydraulic fluid specified in your owner's manual.
* Professional Help: If you're not comfortable working on your vehicle's braking system, take it to a qualified mechanic. A clutch system leak can lead to inability to shift gears, and improper bleeding can cause damage to your clutch system.
This guide provides general information. Always refer to your vehicle's service manual for detailed instructions and diagrams specific to your 1991 Ford F-250. This will ensure you have the correct parts and procedures for your particular model and transmission.
