Tires: Plug the Plug, steel belts, ford mustang

Question
Jack,

I drive a 2001 Ford Mustang (without anti lock breaks) that has a slow leak in one of the tires. The tire with the leak had a plug put in about two months ago.  Aside from the slow leak, my tires seem to be in good shape.  I had all four replaced about 20 thousand-miles ago and these are supposed to be 40 thousand-mile tires.  They have been used under normally conditions and I've rotated them regularly (no racing or anything like that).   

Would it possible for me to have the plug repaired?  Would fixing the plug be a smart decision, assuming that the leak is actually coming from the plug?  If I need to replace that tire should I have 4 new tires put in?  As you can imagine I don't want to spend the money on buying 4 new ones if I don't have to.  

By the way, my steering wheel shakes when I break.  This could be a separate problem, but I just thought I'd let you know in case it's somehow connected to the leak.

Thank you for your help...it is truly appreciated.  

Answer
Steven, I would not repatch the one tire. If it is leaking replace it. You could replace the one but I would run it on the back.  Better yet I would buy two new tires and put both on the back. plugs can be bad news if not done right. It can let water get into the steel belts and cause them to rust. Once that happens the leak continues to get worse.