About a month or so ago I replaced the power sterring pump on my 87 ,for the first three weeks all was well.Then I started seeing drips of oil where I had parked.Since it has not has an issue of leaking oil I did some looking and found one of the lines going in the back of the pump was leaking.Found that it was the nut had loosened,so I tightened it up and checked the fluid level.My question is this,is it common for that to loosen?Thanks