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The front brake on my 89 Suzuki was dragging. I took the caliper off and the pads out, pumped the pistons out about 50%, then cleaned the exposed surface of the pistons. I compressed both pistons many times before they freed up enough where I could compress them with my hand.
After working on them for a while they finally started working right. When you pumped the master (no pads just the caliper) you could see the pistons extend. When you let off the brake lever they retracted very slightly I reassembled the caliper, pads, and brackets as well as cleaned and lubed the pins in the sliding portion of the caliper.
Now when I apply the brakes and release them the front wheel will spin several revolutions when i get it going with my hand, just like the 94 (same type bike).
The bike is 25 years old and I would wager the brake system has never been "serviced" properly. In disc brake systems the pistons move very little and they tend to get gunk accumulated of the exposed portion of the piston even with good dust seals. When the pads are replaced and the pistons compressed, that gunk can prevent the piston from moving properly, especially when the brake is released. At a point you get some brake application continuously, like what was happening with my bike. I could feel the drag and the front brake was very touchy.
While it may help to install springs to retract the pads from the rotors, it has been my experience that a good cleaning of the pistons and moving them in and out many times could get them to release more , as mine did, and prevent them from dragging and costing you mileage.
I had changed the brake fluid before, but after this I may do it again, to flush out any grunge that might have broken free.
regards
Mech
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