Clutch Pedal - Slow Return In Extreme Cold
85ford01Article No. 85-1-20
CLUTCH (HYDRAULIC - SLOW/ DELAYED RETURN - COLD WEATHER)
LIGHT TRUCKS 1983-84 F-SERIES
Vehicles operated at temperatures below -20~F may encounter sluggish pedal return due to the clutch release system fluid thickening. Dow #470 brake fluid can be substituted to improve system pedal return.
NOTE: This fluid may cause the clutch master cylinder and/or slave cylinder to make a slight squeaking noise. The noise will not affect the clutch system operation. It is therefore recommended that the use of low temperature fluid be limited only to environments where minus 20~F is regularly encountered.
The following procedure is used for the hydraulic system installed on the vehicle for draining the fluid, filling the system, and bleeding the clutch system. The filling procedure is done by gravity.
1. Clean dirt and grease from the cap of the clutch master cylinder.
2. Remove the clutch master cylinder cap and diaphragm and syphon the hydraulic fluid from the reservoir. Fill the reservoir to the top with Dow #470 brake fluid only.
3. From under the vehicle loosen the bleed screw located in the slave cylinder body next to the inlet connection and allow gravity flow of fluid into a suitable container.
4. Hydraulic fluid will now begin to move from the master cylinder down the red tube to the slave cylinder. NOTE: The reservoir must be kept full at all times to ensure no introduction of air into the system.
5. At this point, bubbles may appear at the bleed screw outlet. This means that air in the system is being expelled. When the slave cylinder is full, a steady steam of fluid will come from the slave outlet. Tighten the bleed screw.
6. Fill the master cylinder reservoir and assemble the diaphragm and cap to the reservoir. The fluid in the reservoir should be level with step.
7. Exert a light load (approximately 20 lbs.) to the slave cylinder piston by manually pushing the release lever towards the front of vehicle. Loosen the bleed screw while maintaining a
constant light load. Fluid and any air that is left will be expelled through bleed port. Tighten the bleed screw when a steady flow of fluid is visible and no air is being expelled.
IMPORTANT: Tighten the bleed screw before releasing the load on the release lever or air will be sucked into system.
8. Add fluid to the reservoir to level at step. Assemble the diaphragm and cap.
9. Again, exert light load to the release lever as in Step 7 (Do not open bleed screw). The piston in the slave cylinder will move slowly and firmly down the bore. Release the load slowly; if the lever feels spongy, repeat Step 7. Check for air in the red tube. If air is present, force it into the master cylinder by tapping on the tube. Repeat 2-3 times.
10. From inside the cab, actuate the clutch pedal slowly and check for air in the red tube. If air is present, fluid movement will force air into the reservoir. Repeat 2-3 times. ll.The hydraulic system is now fully bled and should release the clutch. Check the vehicle by starting the engine, pushing the clutch pedal to the floor, wait 5 seconds, and select the reverse gear. There should be no grating of gears; if there is, the hydraulic system still contains air, and the procedure from Step 7 must be repeated.
PART NUMBER PART NAME CLASS
- Dow #470 Brake Fluid Procure Locally
OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: "INFORMATION ONLY"