I have an 83 f150 that sat for about a year and now the brake pedal will not return all the way. Is this the master cylinder or the booster or something else all together? I don’t think it has a return spring.
Could be either. There’s a return spring inside both the booster and the master cylinder I think. Not sure, but possibly a collapsed rubber brake hose or sticking wheel cylinders or calipers could cause something like this too. I think if I had this problem as a first experiment, I’d clamp off all the brakes at once at their rubber brake lines, and see if it is still sticking.
Hwo much free play is there? An inch of free play at the top should not effect your brake light switch or braking.
A good bit it stays about have way down and tests on a mild incline indicate that the brakes are applied enough to prevent rolling.
I would think an '83 that set for a year and now has a sticking brake pedal needs a complete brake overhaul. That means new caliper cups rebuild or wheel cylinder rebuild. The rotors/drums should be OK but check for wear. Then new brake lines and a master cylinder rebuild. Then new fluid. That would be just for safety but if it cures the problem that’s a bonus. If it doesn’t cure the problem install a new/rebuilt booster. Brakes are not something to get cheap on.
Feel each wheel after a short trip.One wheel will be significantly hotter then the rest if its a sticking caliper. The hot metal smell from cooking brake pads is a good indication of a seizing caliper.Do not delay this repair because brake pads will wear extremely quickly on that side.
If you are not mechanically inclined, take it to a shop and have the brakes inspected. If you can do some of the work yourself, I would take off each wheel and inspect what the brakes are doing. Do the pads make contact with the rotor when you press the brake pedal, do the brakes properly retract when you let go off the pedal? I don’t think a complete overhaul, as suggested, is necessary, not know the condition the brake system is in.
As far as the pedal not returning all the way, I think George has some good recommendations to look at, while inspecting the brakes.