Goodyear Brake Master Cylinder parts

[Capt Bob]

Need 1" cup seals for Goodyear brake master cylinder #511738/218073-2. Original Goodyear part no. 217957-5. Automotive cannot be used as they are not compatible with aircraft H-5606 mineral based hydraulic fluid. I believe Nitrile compound is impervious to any type of fluid, but I cannot find such a cup seal made of Nitrile. Any ideas would be much appreciated.

Thanks in advance, Bob

[WLIU]

What type airplane? The Swift I think has those types of brake master cylinders.

Best of luck,

Wes