Baffling break problem on minivan

In park with your foot firmly applying the normal brake peddle, set release set release the parking brake to see if the gives you back a firm peddle

Thanks for the tip. I guess I’ll have to wait for the brakes to fail again to try this.

geeze i forgot the booster gets hard when it looses vacuum

boy what i would give to have half a brain. (or at least the half i have forgotten)

the MC is possible as an air entry source no?

either an improperly bled or a leaking MC could allow the phantom air entry.

If the vehicle has rear disc brakes

We just had a discussion a few weeks ago on this topic. My 2002 Sienna has rear drums, but the rear brakes are indeed only adjusted by using the parking brake. It is so common that people never apply the parking brakes, even though using them when parking anywhere except flat ground is basic car safety, that some dealers routinely recommend adjusting rear brakes as part of standard maintenance, without even asking if you use the parking brake.