Sounds to me like your mechanic should come out and tighten the hose clamps for you.
Well, lets see. I am 160 miles from home. The thermostat housing is connected to the upper radiator hose, not the lower. I checked all of the connections and clamps, and the problem is the water pump leaking from the weep hole.
How is my mechanic driving 320 miles to tighten hose clamps going to fix the problem?
His RV must be a rear-wheel drive vehicle, so there should be ample room to do the job.
This is a van based motor home, so the water pump is under the A/C unit and behind the fan, under the fan shroud, next to the alternator. I might have 3 inches between the radiator and the front of the fan. Looks like a fun time today. (Once I have my pot of coffee, that is.)