Join Date: Jan 2019
Location: Sedgwick, Kansas
My guess is that the brake booster has failed. has the engine been 'stumbly' too when you step on the brakes? If you push super hard, does the car slow/stop?
Being that the '70 has a dual master cylinder, it's unlikely that both sides of the master cylinder have failed at once, so my bet is that you either have a leaky hose, or that the booster itself has a leak. They have a big rubber diaphragm inside, and those will get brittle and fail over time.
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