Change Clutch Slave Low Pedal Pressure (1 Viewer)

izzyandsue

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So weird thing happened today. Old slave cylinder was leaking a good bit, got a new Aisin and the rod was too short, so using original rod that came with my ‘81 43. Bled the system by gravity, bleeding nipple on the top. But pedal needs 2 pumps to fully actuate. Had some help to pressure bleed it, no air in system, but still that first pedal just goes to the floor. Second works perfect. Any ideas? System is so simple....
 
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The rod that came with replacement was too short, so I reused the old rod. Cylinder is the same. Will try bleeding again tomorrow.
Seems to me that if you are bleeding totally by gravity (no pumping with the clutch pedal) that you would have to make sure the slave cylinder is completely pushed out (rod is pushed as far out as possible) so the slave can fill completely with fluid.
 

izzyandsue

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Seems to me that if you are bleeding totally by gravity (no pumping with the clutch pedal) that you would have to make sure the slave cylinder is completely pushed out (rod is pushed as far out as possible) so the slave can fill completely with fluid.
Good thought. I did bleed via pressure the second time, by holding the pedal down and cracking the bleeder, then close and repeat another pump. Rod seemed all the way out, but will try again and remove the spring too.
 
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izzyandsue

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did you change the master also?
being a 43 no saying what PO's have done to it before.
I didn't, but the master looks solid, made out of dried out and glued coconut husks, stained black with tobacco juice. But that would be the last piece I do. First will try gravity bleeding again, then Phoenix reverse bleed, pedal pressure bleed, vacuum pump bleed, Motive Pressure Bleeder bleed, bleed while facing the rising sun, tilt the cylinder so bubbles get trapped by bleeder valve and push the rod in bleed, and any other combo I can find. For such a simple system, this one got me doing more tries than the ubercomplicated VW systems. Perseverance.... Thank you though, it is in the back of my mind.
 

pjohnson

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I think what @3_puppies was alluding to was a mismatch between master & slave. The 'similar threads' at the bottom of the page probably have the background.

I think @Rainman 's thread has the most recent info about it.
 
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@3_puppies is correct. I have learned twice now the hard way....always change both the master and the slave at the same time, with matching Aisin units...or you'll soon be driving home without a clutch. The price of these is pretty reasonable, so it just makes sense. I have also discovered that a solid bleed with a helper on the pedal ensures all the air is out. I have not been successful with a gravity bleed. Oh, and one more thing, be sure to follow the FSM procedure for adjusting the freeplay at both the pedal, and at the slave rod, then go back to the pedal to confirm final adjustment. All these things I have learned by doing it the wrong way first! Good luck.:banana:👍
 

izzyandsue

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DONE. Finally after a plethora of never ending conference calls all day long, got to it. First try was to unmount the SC and remount with just one bolt, but keeping the bleeder valve as high as possible and the rod down at an angle. Then gravity bleed for about 10 min, keeping the reservoir full (about every 2 mins would be half full). Then close the bleeder, and remount the SC and the pedal was normal hard. Went for a 5 mile drive with plenty of clutch in/out, and pedal remained hard. So I am calling it done. THANK YOU ALL!
 

izzyandsue

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Oh! and as a bonus, the Hazard switch started working again, so must related to the clutch. But the passenger door window won’t go down anymore, so maybe voodoo cursed.....
 

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