A10 Oil pressure relief valve size.

[Jackson]

Sorry to bother you all again.
I'm trying to remove my oil pressure relief valve and the flats are fairly mangled. I need to get the right size spanner/socket on it. Problem is I can't get an accurate measurement a/f.
1.1" is the best I've managed but I'm not convinced, it doesn't seem to correspond to any standard size. Does anyone know the actual measurement or even better the proper spanner size please?
Thanks in advance,
Adrian.

[Bess]

Hi,
    1.1" across flats is correct. 5/8 whit, 11/16 BSF or 28mm metric.

Best wishes...

[Jackson]

Thanks very much Bess.
Adrian.

[Bess]

You're welcome 

[mashermick]

you cant get a socket on because its to close to the crankcase,the flats get rounded with an open ender , I removed the outer part and tack welded on a bolt ,then removed it  with a socket  !

[Jackson]

Ta, I'm  going to try a box spanner and if that doesn't work machine a socket down to fit.

[Bess]

Hi,
    It's worth machining a socket, when fitting a new or refurbished PRV it's important to refit at the correct torque setting (unless you can use a box spanner with a torque wrench). The threads if distorted will exacerbate oil pressure loss between the threads.

Best wishes...

[Jackson]

Ta, it looks like I have one after all but it will need machining to fit.
I'll try after the box spanner arrives, but you're right I won't be able to get a torque wrench on the box spanner easily. I think the box spanner will be safer for getting the old one off, the hex is pretty mangled. SRM suggest tightening up to the fibre washer and then a sixth of a turn if a torque wrench isn't available.
Adrian