Need HELP ASAP on Tri-Pac coolant line plumbing...

[Waterloo]

What would cause the outlet hose on my Tri-Pac to bulge and fail? I inspected the two lines, the Tri-Pac outlet is connected to the coolant hose that goes to the back of the block. The inlet hose into the Tri-Pac radiator is connected to the water pump on the motor.

There is a dual valve shut off in-between. The shut off does not work, but there are two other fittings on that unit, one side may be a direct bypass of the turn off valve, I do not know.

I replaced the Tri-Pac Thermostat, as that is directly in line with my blown hose... But that is on the outlet side. I do not see how that could pressurize the hose enough to blow a hole in it. Any thoughts?

Do I possibly have my coolant lines reversed? Where my line attaches at the back of the water pump. Is that sucking coolant or is it pushing coolant out of that port at the ISX water pump?