Cannot get purchase on small square nut to bleed rad

[MoJo jojo]

I need to bleed one half of my rad. But the 3 different keys I have used have been unable to open or loosen the small square nut. I have tried a quick blast of WD40 to loosen it with no joy. The small square nut is so stiff the keys have ended up rounding off the edges making it more difficult to get a purchase on it. Can anyone suggest how I can overcome this problem

 

[mark333]

Hi
after wd 40 try tightening the pin a tad then undo.
mark

 

[MoJo jojo]

Thanks for replying mark but I am unable to get any purchase on the little nut in either direction because the keys have rounded of the edges. Do you have any other suggestions at all?

 

[mark333]

In that case i would put a new bleed valve on the other side of the rad(if there is a hole for it) they are only a couple of quid from a plumbers shop
PS some bleed valves can be removed while the pin is in if yours is this type remove the stuck valve and replace it ,2 minute job.
mark

 

[MoJo jojo]

I will have a look tonight.
cheers mark

 

[ChrisR]

File/grind the key as though it was sharpened in a pencil sharpener. Then it'll grip the square lower down. Or cut a slot across it and use a screwdriver.
I use a fine-nosed self-grip wrench, Vise-Grip or Mole. Works every time.

 

[MoJo jojo]

Might sound a silly question but what does a fine-nosed self-grip wrench, Vise-Grip or Mole look like? as I might already have one but am not familiar with the name.

 

[ChrisR]

Yes it is a silly question -try google.

I use baby ones with long bent jaws.