Fuel leak from this joint

[roll]

Hi Team
I have a slow drip of fuel from this joint having had some work done on the car recently. The black tube is the one bringing fuel from the fuel pump across the engine bay. I wondered if I could simply tighten something a little, but when I put a spanner on the “bolt“ nearest the float chamber everything turns so I am not achieving anything. Also I don’t seem to be able to hold one “bolt“ still and turn the other. Could somebody explain how this joint works e.g. is there a thread on the brass (?) tube coming out of the float chamber, can the bolts be separated etc. I am loathe to try and turn anything very hard at present for fear of making things worse. Many thanks.
Peter

 

[cobraboy]

In your first picture, the smaller hex nearest the float chamber has a brass olive underneath it, this forms a compression joint around the tube from the float chamber, there is no thread on that tube. If the joint is not tight both hex will turn.
The joint is tightened by holding the larger hex with a spanner and tightening the smaller hex against it with another spanner.
You can undo the joint to look inside to understand how it works. When undone it may be possible to slide the small hex along the tube to allow you to wind a little PTFE tape around the olive.

Be wary of overtightening, just tighten enough to stop the weep.

 

[jp928]

Check the olive, it may be distorted from over tightening. They can be bought.

 

[roll]

Hi again

I took the joint apart as suggested. I was worried that the tube does not seem to be straight coming out of the “T” joint on the float chamber, and therefore very nervous about cross threading when I put things back together. Also I couldn’t take the inner hex off the tube. Anyway, as per photo the joint is back in one piece. I ran the car for about 10 minutes and everything looks dry, so I will take another peek tomorrow after the drive to work!

Many thanks
Peter

 

[cobraboy]

Don't worry about it being out of line, it will likely crack if you try to get it straight.