Feb 252013
 

the heater doesn’t blow hot air and I”ve noticed the heater hose from the water pump is not warm either
I have changed the thermostat

  One Response to “1995 chevy truck”

  1. Since you have replaced the thermostat, I am assuming that you have bled the system afterward. If you haven’t you may still have an air pocket in the system.

    For testing purposes, you will need to make sure the system is bled and full of coolant. Run the engine till it reaches normal operating temperature. Around 180-210. At this point you will need to check the upper and lower radiator hoses to make sure both are getting hot. The top hose will feel hard or under pressure until the thermostat opens. once the thermostat has opened, the upper hose will relax a little. If you do not feel the hose getting harder or under pressure, replace the radiator cap.

    At this point, you will want to feel the heater hoses at the firewall. Both should be hot. If only one is hot, then your heater core is clogged and will need to be replaced. If both are hot, then you should get hot air from the dash when you turn on the blower. If you do not, you may have vent blockage or separation in the dash.

    Basic Cooling System Plumbing

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