Original AC fuel pump on Herald, run dry as a backup?

[DippedHeadlights]

I'm fitting a new SU fuel pump to the Herald. One option now is remove the original AC pump and fit a blanking plate but thinking is there any issue with leaving it there? Will be no fuel going through so it'll be pumping "dry" but with it there it would be easy to switch to it as a backup if the electric pump was to fail.  Obviously the oil side of it will be fine. Only issue I can think of is the rubber diaphragm could fail if it's not being lubricated/cooled by fuel. Is that a known issue? If it is then I won't bother and will just remove it as having it as an emergency backup then finding when you need it it doesn't work is worse than having it not there at all! 

[johny]

Itll certainly get plenty of 'use' as it'll never stop because its reached the correct pressure😁 Then if you do need it it'll probably be knackered so as a very quick job to install by roadside why not keep it in the boot?

[Pete Lewis]

+ 1 for remove it and keep handy .

running it  dry is not going to work when you need it ,  

Pete

[johny]

Yes it'll continue to wear your cam (even faster?) as the spring will still be compressed on every stroke and I have seen photos on here of grooved cam lobes especially with thin bladed after market pumps😭 Reminds me, I must have a look to see how mines getting on...

[DippedHeadlights]

Good points. I'll remove it and keep it as a spare.