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My Civic has a separate fluid reservoir for the hydraulic clutch system. I bled it last week with the method outlined below and it went great.

My Yaris shares a single reservoir of brake fluid for the brake and clutch systems. This threw me off and I'm not sure if my technique needs to be modified, but I went ahead and tried it and it didn't produce great results, the pedal is still squishy, so maybe I need to either just do more pump cycles or there's something I don't understand and the technique is no longer valid when the reservoir is shared.

This is the technique I was applying (2-man):

  • attach PVC tube to clutch bleed valve, with other end submerged in couple of inches of clean fluid in a clear bottle. Keep the bottle elevated higher than the bleed valve to prevent air entering the valve
  • assistant pumps clutch pedal once slowly as you open the valve and keeps pedal on floor
  • close valve
  • assistant brings pedal up to the top again
  • repeat a bunch of times whilst keeping the fluid reservoir above the MIN line

I noticed a difference as well. With the Civic (dedicated clutch reservoir) the pedal sits on the floor and doesn't rise again between pumps; the assistant has to lift it up as there's no pressure cos the valve was open during the pedal depression. But the Yaris (shared reservoir) pedal comes back up again between pumps. Even though we've just watched fluid (and air perhaps) squirt into the bottle whilst the valve was open. How can the pedal come back up?

Is this pertinent or just a red herring?

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Shared or separate reservoirs the method to bleed is the same, just don't run out of fluid.

The pedal not coming back up depends on where the return spring(s) are - some have one on the pedal box as well as a small one in the slave cylinder. Others may only have a stronger one in the slave cylinder, so it may be the spring in the pedal box has come off or has broken.

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  • What if I stop after only bleeding the clutch and doing nothing to any of the brake bleed valves? Can air in the brake lines every produce a squishy clutch?
    – sphere
    Aug 17 at 22:42
  • 1
    No, separate circuits except for a shared reservoir.
    – Solar Mike
    Aug 18 at 3:46

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