FUEL SENDING UNIT ASSEMBLY LEAK (NEW O-RING)

[BOUDREAUX]

I have a 92 Q45 and have changed the fuel pump twice with no problem. Each time I replaced the o-ring. This time, as before, I installed a new o-ring and pump. I filled my tank and began to smell gas. I thought maybe a line was loose or perhaps one of the smalled o-rings was pinched, but all was good. However, there was gas seeping from under the sending unit assembly plate. I removed the bolts to inspect the o-ring and it looked fine. I reinstalled the sending unit assembly and the thing still leaks. I used a crossing tightening sequence. Could I have the wrong o-ring or over tightened the bolts? I ordered the o-ring (Genuine Ifiniti Part) from an NICO approved source.

Boudreaux

[maxnix]

Tough to say. Torque is a difficult thing for even a professional mechanic to sense accurately. Most of us didn't use a torque wrench on reinstall though.

Investigate more closely. Didn't put the old O ring back on by mistake, did you?

[goody90q45]

......Investigate more closely.

When you pulled the sending unit out the last time did you notice that the o-ring was properly seated in the groove on the gas tank? It's a big skinny o-ring so it wouldn't be hard to twist it out of place when installing the sending unit. If you think this is the problem the o-ring can be held in place with a few thin, 1/8" wide strips of vinyl tape.

Also check the o-ring groove on the fuel tank and the mating surface on the sending unit lid. Are they both clean? No debris?

Finally, check the o-ring with a little WD40 on your fingertips feeling for any small nicks. Run it between your fingers in both directions. If its the right size o-ring it should be the same circumference as the groove and lay in the groove with little slop. I can't find one to measure the material thickness but it should be taller than the groove so that the sending unit compresses it. Good luck.

[Q451990]

I think I would just replace the o-ring and see what happens.

Heath