installing a new oil cooler on my buddies 7.3. im a cummins guy but i figured i would help him out. got it out fine and took it apart fine now im trying to get the three pieces back together, and nothing will go back together. i dont want to break them or anything like that. any tips or tricks?

 

Use your body weight to force it together. Make sure you lube up the new O rings.

 

A good press works well also