Disc brakes pulsating

[1969CoronetR/T]

I had my 1969 Coronet R/T manual drums converted to non-power disc brakes last year and they worked great all summer and fall 2017. I put it away for the winter and went to take it out after a four or five month hibernation and noticed that the brakes were pulsating slightly when applied and it stopped fine. Could this be due to condensation in the lines?

 

[dryheat]

Pulsating usually indicates a warped rotor(s) or perhaps pads that aren't true.

 

[PlainfieldCharger]

Many times the brake rotor oxidizes on the surface at a different rate than the area the brake pad rests for periods of storage. So when you take it out for the first run the surface will even out. This would only hold true if the brakes were fine when the car was first stored.

 

[1969CoronetR/T]

That makes sense since I did not move it for four months. It did seem to improve slightly after driving it around for a half hour. Hopefully I can take it out soon to see if it goes away. Thanks

 

[dan juhasz]

Like Plainfield charger said, if the pads, especially metallic pads remain in contact with the rotors for an extended period that area on the rotor will rust. Worst case scenario is you'll have to remove them and have them resurfaced on a brake lathe. Next year retract the caliper pistons so the pads don't touch and spray rotors with a wd40 type product

 

[miller]

One other thing, that can happen with disc brake rotors, is through use they can get a 'hard spot'. It's caused by the casting not being even. Usually it can be seen, the spot/area will look different from the rest of the surface. Will be harder and not wear down like the rest, and makes a high spot...that will make the brake pulsate. Only cure is a fresh cut on the rotor. I've seen that a few times.

Though, sounds like your's is trying to straighten out.