How old is the hose? There was probably a weak spot in the hose. It could have been rubbing against a fan belt or a part of the car that just rubbed it till it broke. Your Radiator cap could be faulty therefore the pressure in the radiator becomes so great that something has to give and the hose would be a likely part to burst.
The lower radiator hose supplies the water pump. The upper radiator hose supplies the radiator.
The thermostat has not opened yet.
Lower radiator hose.
water pump (has a pin hole overflow if goes bad) , water hose connection, overheating, damage to the radiator causing a crack?
Under normal circumstances it will have some pressure just less than the bottom hose. The bottom hose is directly pressurized by the water pump while the upper hose acts as a return hose to keep the water flowing through the engine block. If there is no pressure you could be low on radiator fluid (water/anti freeze mixed) or have a thermostat stuck open.
It will be the same pressure that burst the silicon radiator hose whether you use water or air to burst it. The difference is probably the hose is designed for use with pressured water or use with compressed air.
That would be a vacuum hose with a hole in it, burst isn't usually a term I would use with a vacuum hose as it tends to imply pressure pushing out.
You may have overheated the engine or seized it.
Either the radiator hose is loose where it connects to the radiator or there is either a small hole in the radiator or in the radiator hose. Try checking the hose to see if it's loose or check for small holes in the hose or radiator.
Weak solder joint when mfg.? Excessive water pressure due to: 1) Bad radiator cap 2) Plugged radiator 3) Thermostat not opening 4) By-pass hose crimped or plugged 5) Leaking head gasket(s) Possibly the radiator hose was weak. So in other words, a bad radiator hose.
Most radiator hoses burst due to old age or rubbing against an engine part once it bursts you will lose antifreeze rapidly due to the pressure causing your car to over heat.
You need a need radiator cap. you need a new hose
The lower radiator hose is located at the bottom of the radiator.
In most cases the lower radiator hose feeds the water pump. The upper radiator hose feeds the radiator.
Look on top of the radiator and follow the hose from the radiator to the thermostat housing. Look on the bottom of the radiator and follow the hose up to bottom of the block.
Should be at the bottom or rear of radiator or remove lower radiator hose
a hose clamp