Just want to put a plug in for Apple Hydraulics in NY. I had them sleeve a master cylinder for me for my '69. I reassembled it myself after getting it back. When I had problems which turned out to be not a result of their work, they were very patient and helpful. I sent the MC back to them and they disassembled, checked and tested it at no charge. Even installed new bleeders in it. I would recommend them.

able to finally find the problem von?

Yes. It was air in the rear lines. See my post in the "What Could Be Wrong" thread a little further down the page.