Should work.
Mine is a bit different in that it is mounted on the expansion tank which has its main outlet plumbed to the inlet side of the pump.
nice to have a pressure reading as any pressure close to your cap rating shows coolant being ejected.
I had a coolant failure on first flight thanks to a hose clamp skipping a tooth just at 200' and had to complete a low level circuit. the coolant obscuring vision gets your attention pretty quick! but its not the end of the world, these motors seem to keep going ok, although I dont think a go around would have been good idea, the motor was running fine all the way back to the hangar and was nicely steam cleaned under the cowl for the subsequent rebuild, had no damage so just replaced all the soft parts.
On the coolant O'rings, I just bought enough cord from my local industrial supplier, cut them to length, superglued the join & had it all back together in no time.