My brother's wife has a problem with her 1988 Subaru GL Wagon. The car has more than 100,000 miles on it and it has now blown three hoses in the past four months.
She also says that the engine runs hot when on the highway going above 55mph. Is the problem simply old hoses or is it something else?
The hoses are probably showing a need for replacement at eleven years and a hundred thousand miles, regardless, but three in four months sounds like there may be excessive pressure within the coolant system.
The first thing to check for is a possible blown head gasket or cracked cylinder head. A simple way to determine if combustion chamber pressure is being transmitted into the coolant system is with the use of an emissions analyzer. By removing the radiator cap and placing the analyzer's probe slightly above the coolant, we can check for excessive hydrocarbons. If the test shows positive this confirms a cylinder head or gasket failure. You can often make the same assessment by simply taking a good whiff of the coolant and getting an obvious scent of exhaust.
If the coolant system is free of hydrocarbons, the next possibilities would be a partially obstructed radiator or a stuck closed thermostat. Either would also explain the high coolant temperature at highway speeds. Removal of the radiator would be required in order to have it flow tested, and the thermostat should be replaced no matter what.
Also be sure there are no significant air current restrictions at the front of the vehicle, and coolant fan operation is normal.