Fuel line will not tighten into Sedimentor

[simonpelly]

Hi Folks,

Defender 1997 110 300 Tdi.

After fitting a new sedimentor, now struggling to get one of the fuel line fitting connectors to tighten.

The connector on the short fuel line from the tank to the sedimentor tightens no problem. Image with the longer thread.

The connector on the long main fuel line from the lift pump will simply not tighten on the sedimentor. The threads engage, couple of turns of the spanner and then it pops back out again. Image with the shorter thread.

Measured the thread widths on both connectors at 12.56mm and 12.50mm respectively.

Also tried to swap them over, it is always an issue with the main fuel line connector. No issues with the shorter fuel line.

Any thoughts? Both fuel lines are new as is the sedimentor.

Thanks,

Simon...

Edited May 15, 2021 by simonpelly

[Eightpot]

Always a fiddle to get them lined up and screwed in with the fuel pipe pulling it off centre, same as brake lines,  and very easy to cross thread unfortunately- I never use a spanner till I've got a good few turns in by hand.  If you have one of the old fittings with no pipe on, maybe try screwing that in to clean the thread up and do a sanity check.  Patience, no force, no spanner till you've got a few turns on. 

[pete3000]

I'd guess at the wrong thread? the blanking plug for the 562748 sedimentor is listed as 517689 and the matching union nut for a series 2.25 is 517690. Can you compare the threads on a blanking port against your pipe fittings? could be 1/2" unf

Pete