My 108 car, a 1972 280SE 4.5, has a problem with all four brakes sticking from time to time. This occurs after the car has been driven a ways and goes away after the car cools off. I suppose it could be the flexible portions of the brake lines but it would seem unlikely since all 4 corners stick simultaneously. My local indy suspects it's a booster problem, and I also suppose the master cylinder could be at fault. How does one test these parts of the system? Any thoughts or advice would be welcomed.

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1972 280SE 4.5

if they all stick at once it most likely is items before the lines, that would be master or booster. I would think its at the master. when was the Last time the brake fluid was completely drained? Reservoir cleaned? Look for any signs of air infiltration in the booster vacuum line as well

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Ron
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When I replaced the MC, I received a defective unit that was leaking past its rear seals. It was preventing the pedal from returning. I'd start by disconnecting the MC from the booster and pulling it forward to check for fluid at the interface. While it's separated, push the pedal and observe if the booster is causing binding. That will help isolate the culprit.

FWIW my old 108 did the same thing when the MC was dying.

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Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

Previous:
1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k