Cold water tank valve leak

[Bobharford]

Hi
Help!
The tank in the loft which feeds the hot water boiler is leaking throuh the float valve. I have changed the washer and bent the float arm but it is still leaking any other things I can try? the float has no leak in it.
Pulling the arm manually up stops the trickle but it sinks down a little and the trickle resumes
I had thought of changing the whole assembly but when I try to spanner it off it just rotates on the threads any way I can free this!

 

[pipme]

Edited
Oops ! Just fully read post ..... Need to turn nut on the outside of tank which is captive, but rotatable, on the supply pipe, whilst holding assembly on inside ... tis that way on mine anyway.
Could need a good dose of WD40 at the threaded joint and allow to soak in for a while.
-----------------o0o--------------------
If successfully removed then you could do worse than one of these, have been using same in very hard water area for 10 yrs replaced only one equivalent of 'washer' .... IMHO good piece of kit and easy to fit.
The picture shows the valve assembly rotated clockwise by 90°, don't know why, probably to fit the format used, (the threaded portion fits through side of tank) ... all required bits in the kit.

Fluidmaster quiet float valve, for high and low pressure. From sheds like B&Q etc

P

 

[Bahco]

Can't you just undo the large brass nut near the water entry and fit a new float valve. There is really no need to change all of it except in extreme cases and should take no more than a few minutes