Word of warning after spending a great deal of time fixing a problem yesterday. We all carry spares of every single part on the van so we never have any down time, but...
We use the grey 1/2" John Guest fittings for part of the delivery system. The one leading into the Shurflo was dripping yesterday so I tightened it a little. "Tink". It broke. Now water's spouting into the back of the van. I bodge the end of the hose shut so it's barely dribbling and get the spare pump out of its box (cant use the old one thanks to the stub of the connector). Pop in the new fitting on one side then take the old one out of the other side of the old pump. I go to screw it into the new pump and even before all the threads were in, "tink", that one breaks as well. Took a (long) while to bodge a repair that didn't leak.
Moral of the story is that if you use these types of fittings, they clearly weaken with age so you might want more than one spare on the van as you may have trouble reusing old ones.
These ones:
Vin