XJRider.com

hi i am having trouble with oil coolers , i keep getting oil leaking from the banjo joints first it was on the right side to find out that where the banjo bolt screws in it had a crack down one side, so i bought a second hand one off ebay, if all looked good (no cracks) bought new banjo copper washers and put all back together and tightening at the right poundage , to now find out its leaking on the left side. took the cooler off to find out there is a crack in the left one.
i have just ordered another cooler. so can any one tell me how i am going wrong ..............