Sudden problem with my brakes...
I just got my 1950 Chevy Sport Coupe back on the road after sitting for about 10 months during an engine swap. Got the car on the road the other night and drove it around with no problems. Today I took it out and was driving for a while around town. I went to pull into a parking lot and applied slight pressure to slow down. The right rear tire immediately locked up and I slid right past the driveway. I released the brakes and then re-applied and they worked normally. I did not apply the brakes hard, just enough to slow down. The same thing happened about 10 minutes later. Was only going about 10 MPH at the time applied the brakes lightly, and locked the right rear again. The rest of the car continues on, barely slowing down when this happens. The last time it happened I was pulling out of the gas station onto the main road. Was at idle, going about 5 MPH this time and hit the brakes, again locking the right rear but the rest of the car continues on.
This all happened over the course of driving the car for about 2 hours. Must have hit the brakes at least a hundred times during this period and only had the right rear lock up three times. Needless to say, scary when it happened.
The brake system is manual with stock drums all around. Single reservior master cylinder.
What do you think may be causing this?