IB238

Clutch Hydraulic Release System Bleeding Procedures


The master cylinder for these applications is mounted on the firewall at an angle that creates an air trap and makes bleeding bery difficult or impossible. The pressure line to the Concentric Slave Cylinder (CSC) often includes an air trap in the line as it crosses over the vehicle frame, refer to Figure 1 on page 2. 


NOTICE: Clutch hydraulic systems or components must be properly and completley bled in order for your clutch to function correctly. Difficult shifting or inability to select a gear is often due to air in the hydraulic system.  

CAUTION: Brake fluid damages painted surfaces. Please refer all to cautions and clean up procedures on the brake fluid container. Refer to the vehicles owners' manual for specific fluid specifications.


  1. We recommend that you start by bench bleeding the master cylinder and pressure line as a subassembly prior to installing int he vehicle, see Figure 1.
  2. Master cylinder replacement. Carefully drive out the retaining pin from the old master cylinder and install the new master cylinder using the new line seal and retaining pin. Inspect the fitting for damage priot to reusing it. Do not install the master cylinder pushrod at this time. 
  3. Install the new O-ring and sliding sleeve on the pressure line connector.
  4. Remove the reservoir cap and diaphragm boot, fill the reservoir with fresh DOT 3.
  5. Position the reservoir, master cylinder and line as shown in Figure 2 by carefully pulling the end of the pressure line downward, this allows air to flow up into the reservoir and DOT 3 will flow down into the system. 
  6. Using a 4" No. 2 Phillips screwdriver as a subsitute master cylinder pushrod, hold the master cylinder in one hand and push the pushrod into the master cylinder approximately 3/8", repeat several times, refill the reservoir. Continue the process allowing a few minute for the fluid to flow down into the system. Starting from the bottom of the pressure line, tap on the line wth a screwdriver handle, continue tapping up to and including the master cylinder. This helps dislodge air bubbles. 
  7. It will be normal for bubbles to appear in the fluid reservoir as they are expelled from the system. Continue short pushes on the master cylinder pushrod and refilling the reservoir until the pushrod becomes solid and does not compress into the master cylinder body. 
  8. When the pushrod becomes hard and cannot be compressed, check the pushrod movement. The pushrod should compress less than 1/8". See Figure 5 and 6 on page 2. If it can be pushed in more than 1/8" it requires further bleeding, repeat steps 4 thru 7. 
  9. Installed testing: After installation into the vehicle and before connecting the line, push on the clutch pedal lightly with your hand, it should be firm with the less than 1/8" pushrod travel as in step 7. See Figure 3. 
  10. Installation and slave cylinder bleeding. If equipped with the new upgraded retaining clip as shown in Figure 3, DO NOT REMOVE THE RETAINING CLIP from the slave cylinder connection. Firmly insert the line into the slave cylinder. Fill the reservoir with the fresh DOT 3. Attach a line and capture container the bleed screw. Open the bleed screw on the slave cylinder several turns and allow the fluid to run out until air bubles are not observed, check the reservoir fluid level during this process. Allow 1 1/2-2 reservoirs worth of fluid to flow through the system to remove air. Do not allow the reservoir to run dry. Tighten the bleed screw and test for release. If necessary, repeat this step to purge air. 
  11. Figure 4 illustrates the original connection system. Do not remove the internal retaining ring.


The pattern below can be printed and used as a template for a CSC Release Stroke Gage for most Ford applications commonly Rangers and light duty F-Series Pick Ups. Remove the inspection cap on the driver’s side of the transmission, position the narrow end of the gage at the bearing collar as illustrated. Engine off, assistant pushes clutch pedal to floor and holds.

Stroke distance is typically 5/16” minimum for most of these applications.


PLEASE REFER TO FACTORY SERVICE MANUALS FOR DETAILED APPLICATION SPECIFIC PROCEDURES.

This bulletin is to assist in the safe and effective servicing of this application. Transmissions, transaxles and transfer cases are heavy and their safe removal and replacement requires the use of proper tools, equipment and procedures to prevent injury and damage. Always read and follow instruction bulletins and factory service manuals for detailed clutch servicing procedures.

Bulletins and any additional information:

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IB238 06/30/2015