My Daddy has a 1974 David Brown 885 that had sat for around 6yrs. We recently got it back to running. We installed a new injector pump and after having the injectors pressure tested, I had to purchase one new injector. Ive gotten the tractor running but now my problem is I can't get one of the injectors to seal between the copper washer. I have cleaned all the debris out of the head with alcohol and Q-tips. I have been very careful not to over tighten the injector mounting nuts when I initially install the injector but no matter what I do, I can't keep the fuel from leaking by the washer and up past the body of the injector. Any help in this matter would be greatly appreciated.[b:adb24bf001][/b:adb24bf001]