This would be my guess, too. The belt seems to be slipping. Also, make sure you have a proper fit of the "V" part of the belt. Your pulley could be glazed up OR if you got a fluid leak that is getting to this area it could help make it slip. And don't turn your wheel if your not moving will help, too .boba said:Even if the belt looks good at first glance, make sure it isn't glazed. This WILL make the belt squeal and the pump operation erratic.