I suspect that the Aeroquip hose may be the problem. I don't think that the pressure rating is high enough. I'm surprised that whoever installed the ss hard line didn't also install the ss braided flex line to the slave cyl. You can order the ss braided flex line from one of the Pantera vendors or have one made up locally.
As a temporary test, you could get a length (or two) of 1/4" steel brake line from the local auto parts to replace the Aeroquip hose. You will need to change the fittings and reflare the tubing ends. Copper tubing will also work, as this is only temporary.
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