When a new pump is installed you will need to bleed all the air out so you may "burp" air and fluid that may leak a bit out of the reservoir, but nothing excessive. You will need to top off the reservoir after the system is bled (it is self-bleeding). Is your leak only when you drive, at idle, high rpm? If your reservoir is getting pressurized fluid it sounds like you have a stuck open pressure relief valve. What did you set your relief valve at (how many shims)?