I have 1998 outback wagon. This is a follow up to a post of about a week ago regarding grinding noise when turning right into a parking place with the brakes applied. I took the drivers side front pads off and noticed that the outer pad was stuck in the spring clip. I pried out the pad and cleaned everything up. While the caliper was hanging from the spring tower the brake pedal inadvertently got depressed and I noticed that only one of the pistons came out. One reply to my earlier post said only one piston on 1998 outback but it sure looks like two to me.

 

So is it one or two and if two should they both have come out when the brake pedal was depressed? And if yes to that could it be causing my vibration?

I'm pretty sure '98 outback had dual piston front calipers. Both pistons should come out. But if you are pressing the pedal without the pistons touching the rotor, only the piston with the least resistance may start coming out. If you put a piece of 2x4 or some other wood in there so that it blocks the piston that is coming out, then the other piston should start coming out when the first is blocked. CAUTION - don't let the pistons come out very far. Without wood or something there if you press the pedal enough times the piston will come out of the caliper body. But it is possible that the other piston is siezed. If any water gets behind that boot it starts rusting and then eventually the piston gets stuck in the seal with its rust and won't move anymore, or will come out but won't go back in.

 

All contact points between the brake pads and the caliper brackets., clips, etc., except the brake pad friction material itself of course, is supposed to have brake grease on it.