Just replaced my lift pump Monday. Noticed last night that I could smell fuel. New pump is leaking!!! Went to the Freightliner shop today they gave me a new one to replace without giving them the defective one. Put the 2nd new one on and the friggin pressures are lower than the original bad one. How do you explain that you have recieved two defective pumps? I leaving on a 1000 mile trip next week I have got to do something. Should I put the 1st defective pump back on? It appears that the studs that hold the top plate on the pump where not tight enough and that was where the leak was coming from. I can tighten them up put it back on and see if it leaks. I'm getting good at changing these pump can do one in under thirty minutes.

 

If the only thing wrong with the 1st pump was that it was leaking, and you know the source of the leak, it can't hurt to try it again. Like you say, " I'm getting good at changing these pump can do one in under thirty minutes".