How to replace Dorf kitchen tap?

[kn_ll]

Hi I am planning  to replace my old Dorf  kitchen tap with a lever type mixer. (something like www.bunnings.com.au/estilo-wels-5-star-6l-min-chrome-tall-vege-spray-coil-sink-mixer_p0018950) 

I am planning fit a detergent dispenser to one of the holes and  plug  up to other.  However  I an issue

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How do you remove the lock nut on the existing spout -  see photo?  It appears that a basin spanner  jaws (www.bunnings.com.au/haron-280mm-adjustable-basin-wrench_p4901618) may not be able to fit in the tight space between the top of  pipe and the sink - estimated to be less than 4mm.

[kn_ll]

Thanks @EricL 

Tried adding more  thicker tape to the connection, however it is still leaking.  Rather than liquid sealant would plumbers hemp work just as well?  The reason is how difficult is it to unscrew with sealant applied.   I bought the brass extension because its only 15mm short rather than braided hose to connect hot water.  The fit is not tight enough with tape to seal.  The leak is worse than the tap to wall connection.  Should I would more tape and up to how much?  Am I better off with braided?

Thanks

[EricL]

Hi @kn_ll 

It would be advantageous to you if you were to use braided hoses as they have angled rubber washers that provide an excellent seal. You can go to the next step in seals and use FIX-A-TAP Grey PTFE Uniseal High Density Thread Seal Tape. This is a thicker tape that should provide a better seal.

Please make sure to remove all the plumber's tape that was placed in before using the Grey tape.

If you need further assistance, please let me know.

Eric