Nope. Standard dual circuit design. It's been used since the mid '60's. Prevents you from having total brake loss in the event of a single circuit failure. Having the rear dry is usually an indication (with the exception of a leak) of master cylinder failure. The fluid is leaked into the vacuum booster where it is then passed into the intake manifold and burnt. Check for seepage beneath the M.C. at the booster mounting.

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“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
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