How to Bleed the Clutch

[BlackPlastic]

I was admiring the How-to forum, but this seems to have gotten missed. If you have a Mity Vac, I have found it to be very useful on the sealed hydraulic unit, and it is easier than using the bleeder screw on other cars.


1. Verify that all the lines and fittings are dry and secure.
2. Clean the dirt and grease from the reservoir cap in order to ensure that no foreign substances enter the system.
3. Remove the reservoir cap.
4. Fill the reservoir to the proper level with the required fluid.
5. Attach the J 43485 (Adapter) to the J 35555 (Mity Vac), or equivalent.
6. Place and hold the adapter on the reservoir filler neck to ensure a tight fit. In some cases, the adapter will fit into the reservoir opening.
7. Apply a vacuum of 51-68 kPa (15-20 hg) and remove the adapter.
8. Refill the reservoir to the proper level.
9. Repeat Steps 6 and 7.
10. If needed, refill the reservoir and continue to pull a vacuum until no more bubbles can be seen in the reservoir or until the fluid level no longer drops.

*Caution: The vehicle will move if started in gear before the Actuator Cylinder is refilled and operational. Start the vehicle the first time in neutral to help prevent personal injury from vehicle movement and see if the transmission will shift easily into gear.*

11. Pump the clutch pedal until firm (to refill actuator cylinder).
12. Add additional fluid if needed.
13. Test drive vehicle to ensure proper operation.

[OldNuc]

The problem with that is you will suck air past the seals and it will still be air bound. There is a TSB with that updated method also. If you draw several inches (about 5 inches) of vacuum and then manually push in the operating rod while maintaining the slave cylinder with the operating rod pointed straight down and below the master cylinder it might work. Release teh vacuum before releasing the operating rod and then allow it to slowly extend.

If it works you save the cost of a replacement. But even the TSB did not offer much hope.

[BlackPlastic]

I suppose, if the seals are weak, you'd probably need to replace it regardless. But if they were that bad, surely they wouldn't hold fluid worth a darn under that pressure anyways.

[ssicarman]

The seals are designed to hold against internal pressure. They are not designed to stop air intrusion when the hydraulic system is placed into a vacuum. The seals are cup seals and the lips are facing the fluid.

[BlackPlastic]

Makes sense. Well, they must be able to withstand 15-20 hg at least, because it worked for me. Revived a hydraulic unit that I had lost pressure. Brought the fork travel back to spec

[mrclean92124]

Bleed Sealed master/slave in-car with no mess!

Originally Posted by 00 SLow

I just finished going through hell chasing clutch problems after blowing a hole in the side of my bellhousing. After seeing lots of useful info about clutch related issues in the forum, I thought posting the directions that came with my new hydro assembly would be a be a useful addition. It's clean, dry, and doesn't require disassembling the slave.

I found it easier to bleed with the whole thing installed, with the slave hanging off the trans.

--- Twist the slave cylinder off the transmission, and point it vertically, with the pushrod facing the ground. With the cap off the reservoir, SLOWLY depress pushrod into the cylinder about an inch while watching the reservoir for bubbles. Repeat process until air bubbles no longer appear, usually about 10 to 15 strokes. With the cap still off, slowly press the pushrod in far enough to reconnect the bands on the retaining strap, if not already broken. Reinstall slave and replace the cap. Using short quick strokes, press the clutch pedal 20 to 30 times or until pedal is firm. Under normal usage, small anounts of air remaining will purge itself from the system. ---