SKSpritenodes stop moving when given physics body - swift

Question

When i give two nodes in my game a physics body, they stop doing what i want them to do. I have two bars at the bottom of the scene,one starts on the left, and the other is on the right, and they continuously go to meet at the middle then move back to there starting spot, like a floor opening up. Without a physics body, they do exactly this, but when i give them a physics body,when they both meet in the middle, they stop there and don't move back out.
Here are the bars:
bar.position = CGPoint(x:-self.size.width * 0.2, y:(self.size.height * 0.03));
bar.physicsBody = SKPhysicsBody(texture: text, size: text.size())
bar.physicsBody?.categoryBitMask = PhysicsCategory.bar
bar.physicsBody?.contactTestBitMask = PhysicsCategory.ball
bar.physicsBody?.collisionBitMask = PhysicsCategory.bar
self.addChild(bar)
bar1.position = CGPoint(x:self.size.width * 1.2, y:(self.size.height * 0.03));
bar1.physicsBody = SKPhysicsBody(texture: text, size: text.size())
bar1.physicsBody?.categoryBitMask = PhysicsCategory.bar
bar1.physicsBody?.contactTestBitMask = PhysicsCategory.ball
bar1.physicsBody?.collisionBitMask = PhysicsCategory.bar
self.addChild(bar1)
And this is how they move. This is in the update method:
if (bar.position.x == -self.size.width * 0.2)
{
let move = SKAction.moveToX(self.size.width * 0.012, duration: 1);
bar.runAction(move);
} else if (bar.position.x == self.size.width * 0.012) {
let move = SKAction.moveToX(-self.size.width * 0.2, duration: 1)
bar.runAction(move)
}
if (bar1.position.x == self.size.width * 1.2)
{
let move = SKAction.moveToX(self.size.width * 0.988, duration: 1);
bar1.runAction(move);
} else if (bar1.position.x == self.size.width * 0.988) {
let move = SKAction.moveToX(self.size.width * 1.2, duration: 1)
bar1.runAction(move)
}
What could be causing them to stick together at the middle when i give them a physics body.