Open Bleed Screw Bleeding
Clutch Hydraulic Release Systems
This procedure is similar to traditional brake bleeding but starts with an open bleed screw. The sequence must be followed and only works on a specific design master cylinder, see reference images below. The arrows are pointing to the pressure line connection. Also, the slave cylinder must have a bleed screw. Notice that the pressure connection is pointed up or at the side of the cylinder.
Note: Master cylinders that have the pressure connection at the bottom of the master cylinder are not a good candidate for this procedure. Starting with the system completely connected, reservoir full and if possible a length of tubing attached to the bleed screw directed into a waste fluid container:
1. Start with the pedal up.
2. Open bleed screw.
3. Slowly push the clutch pedal to the floorboard.
4. As soon as the pedal contacts the floorboard, close the bleed screw.
5. Slowly lift the clutch pedal.
6. Repeat steps 2 thru 5 monitoring the fluid level. DO NOT allow the reservoir to run dry.
This process continues to push a charge of fluid down thru the system with the open bleed screw and refills the master cylinder during the upstroke of the pedal. The process repeats sending charge after charge of fluid until bled.
The hose on the bleed screw helps to monitor the progress and watch the air bubbles change to a steady stream of fluid.
Instruction bulletin IB253 addresses adjusting the pushrod. A safe starting adjustment for a new master cylinder is with the pushrod just loose, so the pin can easily slide in. Follow IB253 for detailed adjustment processes.
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: