Hmmm, its been a while but....
Check your maintenance schedule. There is a requirement to disassemble and clean the valve.
Now whilst it is Murphy proof in terms of installing it, it is possible to reassemble the 'internals' incorrectly so it will not operate as designed. It may be quite possible for it to pass no oil and then pass 'some' oil.
I cannot see how a 'smaller' clamp will cause any problems. You just won’t be able to fully close it around the valve when installing it.