GM Storm/Spectrum 1985-1993 Repair Guide



Disconnect the negative battery cable or fan motor wiring harness connector before replacing any radiator/heater hose. The fan may come ON, under certain circumstances, even though the ignition is OFF.


Inspect the condition of the radiator and heater hoses periodically. Early spring and at the beginning of the fall or winter when you are performing other maintenance, are good times. Make sure the engine and cooling system is cold. Visually inspect for cracking, rotting or collapsed hoses, replace as necessary. Run your hand along the length of the hose. If a weak or swollen spot is noted when squeezing the hose wall, replace the hose.


See Figures 1, 2 and 3

  1. Remove the radiator pressure cap.

Never remove the pressure cap while the engine is running or personal injury from scalding hot coolant or steam may result. If possible, wait until the engine has cooled to remove the pressure cap. If this is not possible, wrap a thick cloth around the pressure cap and turn it slowly to the stop. Step back while the pressure is released from the cooling system. When you are sure all the pressure has been released, still using the cloth, turn and remove the cap.

  1. Position a clean container under the radiator drain plug, then open the drain and allow the cooling system to drain to an appropriate level. For some upper hoses only a little coolant must be drained, to remove hoses positioned lower on the engine, such as the lower radiator hose, the entire cooling system must be drained.

When draining the coolant, keep in mind that cats and dogs are attracted by the ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant may be reused unless it is contaminated or several years old.

  1. Loosen the hose clamps at each end of the hose requiring replacement. Pull the clamps back on the hose away from the connection.
  3. Twist, pull and slide the hose off the fitting.

If the hose is stuck at the connection, do not try to insert a screwdriver or other sharp tool under the hose end in an effort to free it, as the connection and/or hose may become damaged. Heater connections especially may be easily damaged by such a procedure. If the hose is not to be reused, use a single-edged razor blade to make a slice at the end of the hose, perpendicular to the end of the hose. Do not cut deep so as not to damage the connection. The hose can then be peeled from the connection.

  1. Clean both hose mounting connections. Inspect the condition of the hose clamps and replace them, if necessary.

To install:
  1. Dip the ends of the new hose into clean engine coolant to ease installation.
  3. Slide the hose clamps over the replacement hose and slide the hose ends over the connections into position.
  5. Position and secure the hose clamps. Make sure they are located inside the raised bead of the connector.
  7. If available, install a pressure tester to the bottle and check for leaks.
  9. Close the radiator drainplug and fill the cooling system with the clean drained engine coolant or a suitable 50-70 percent mixture of ethylene glycol coolant and water.
  11. Leave the radiator cap off, then start and run the engine to normal operating temperature. When the engine is at operating temperature and the thermostat has opened, continue to fill the radiator until it the level stabilizes just below the filler neck.
  13. Install the radiator pressure cap and check the clamped hose ends for leaks.
  15. Shut the engine OFF and allow the engine to cool. Once the engine has cooled, check the surge tank for proper coolant level and add, as necessary.

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Fig. Fig. 1: Cooling system schematic - Spectrum

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Fig. Fig. 2: Cooling system schematic - Storm SOHC engine

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Fig. Fig. 3: Cooling system schematic - Storm 1.6L DOHC engine