I have had a dual chamber master cylinder on my '57 GMC truck for around 12 years now. It has lately started slowly leaking out the point where the activation rod comes into the cylinder. I bought this as part of a kit from one of the old truck parts providers. If they are still in existance they probably don't know what the master cylinder was for. Like most of the old truck parts sellers, they did not supply any real part numbers with their kits while they charge 2X what the part would cost at FLAPS. The master cylinder is for disk front, drum rear. The only serious markings I can find on it are "Wagner 7822". There is an FF between the Wagner and the 7822, but the FF looks stamped while the other characters are cast. I've been hunting on line for a reference to Wagner 7822 with no luck. Tomorrow I'll stop by FLAPS and see if they have paper books for Wagner. Any chance one of you might know what this master cylinder "fits"? That way I could just walk in and ask for a master cylinder for a Hupmobile (or whatever) with front disk brakes.
The only guy I know who can do this is Tommy @ Valley Friction Materials in North Hollywood , Ca. You could send it to White Post restorations and they'll sleeve it ,might be cheaper to buy another one though . I , personally don't like rebuilding those dual circuit MC's , they don't ' take ' well IMO . If it's leaking in this manner , the fluid throughout the entire hydraulic system is prolly contaminated and in need of serious flushing .
