Take a bicycle
pump with a built in pressure guage (PeP Boys $15.00) two tire stems with valves. Remove the hose from the barb at the thermostat housing and insert the bulb end of one tire stem and clamp. Remove the hose from the water injector on the
exhaust, stuff the bulb end of the second stem in that hose and clamp it. Attach the bicycle
pump an pump until the guage shows 20 lbs. (6 lbs more than the standard water pressure) watch the guage for 45 minutes. Should hold at 20 for at least 45 min. If not, you'll know before you go through a tear down.