I recently fitted a JWT flywheel and clutch and last night decided to change the rubber slave cylinder hose to a stainless item, as the pedal was becoming mushy in traffic (heat soak).

The Problem:
After fitting the new braided stainless hose I spent a couple of hours trying to get any kind of pedal pressure. Nothing. Pedal went to floor and just a dribble of fluid and air coming from the slave cylinder. The slave was only moving a little, not enough to engage the clutch at all. Very frustrating.

I have seen old brake master cylinders go bad on much older vehicles when the pedal is 'hyper-extended' past the point of normal wear. Sometimes this sticks the piston in place or pushes dirt past the seal creating wear. This did NOT seem to be the case, despite many forum posts suggesting the master and slave cylinders magically go bad when bleeding.

The Backyard Solution:
The next day I removed the slave cylinder from the gearbox, with the new hose still attached and made a jig to block the slave cylinder piston from moving. It's just a piece of square tube with 3 holes drilled in it. You could use a g-clamp too, but the front face of my slave cylinder was a rough casting not suitable for a flat g-clamp.






NOW, within 4 or 5 pedal pumps using this method, the reservoir level had dropped significantly. After bleeding once, and an enormous flow of air coming out, some pedal pressure had returned. After 2 more bleeds in normal old school style and re-filling the reservoir, the pedal was now rock hard.

After that I simply bolted the slave back up to the transmission and the clutch pedal was fully operational once again.

This method stops the slave cylinder piston from moving and after a few pedal pumps creates a solid pressure and flow from master to slave which then allows you to bleed the air out.

Worth a try if you are having issues.

 

Did you have any issues with the pedal sticking halfway up? I Pretty much swapped the same things plus a new slave cylinder and seem to be stuck with the pedal only coming back up halfway on its own

 

It's basically the same thing I do , but I hold the slave fully collapsed by hand while bleeding