When I was redoing the brake/master cyls. on my truck, I had them all bored and resleeved with brass or stainless steel(your choice)to original specs.,rebuilt with stock rubber kits,and now use silicone brake fluid. Supposed to be less corrosive and not bothered by moisture. My truck is not a daily driver, it could be but its a 1945 2ton 12'flatbed. I read about this proceedure in This Old Truck/Vintage Truck magazine. I am totally satisfied with this...
