Hello
My good friend John Merton from Oz sent me this overnight. I hope it helps you as it sounds like a very similar problem.
I had a similar issue years ago with a 4/4 Series 1 which had been converted to hydraulics using the essentially same approach as the early hydraulic systems on the later Morgans.
The problem was that, in this case, one of the slave cylinders at the front had a bleeder screw issue. When you pumped the pedal the system would suck air back in past the worn thread on the bleeder screw. It didn’t help that the slave cylinder was of the type that had a ball bearing under the bleeder screw.
This had been missed by the local Morgan agent and a number of brake specialists, and someone had actually hammered the brake pipe along the front crossmember to the front left flat obviously to try to “isolate” it.
I spent a full day with a friend to no avail trying to bleed this side. I had a thought bubble early next morning (about 2am), and at dawn called my son- in- law over to test my theory. I put some plumbers’ tape around the bleeder screw, loosened it off so that he could pump and then had him hold the pedal down while I tightened the screw. We then repeated the process. Two pumps and the brakes were fixed.
This may or may not help.
