How about using two small wood clamps with a couple of pieces of wood each to
clamp the hoses coming into and going out of the valve.  Then when you remove
it you will lose a minimal amount of coolant and probably will not need to
rebleed (I leave this up to you).  I have never tried this, but it would work
as long as you have enough space to get the clamps on the hoses.
Hope this helps.

Ken Wilford
http://www.vanagain.com
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