Astro, Safari 1997-2005

Removal & Installation

Print

The thermostat is located at the front of the intake manifold.

  1. Disconnect the negative battery cable for safety.
  2.  
  3. Place a catch pan under the radiator, open the drain cock and drain the cooling system to a level below the thermostat housing.
    CAUTION
    When draining the coolant, keep in mind that cats and dogs are attracted by 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 should be reused unless it is contaminated or several years old.

  4.  
  5. Remove the thermostat housing-to-engine bolts or bolt and stud, as applicable,
  6.  
  7. Separate the housing from the manifold and carefully remove the thermostat.
  8.  
  9. Using a plastic scraper, clean the gasket mounting surfaces.

    Click image to see an enlarged view

    Fig. Exploded view of the thermostat and housing assembly-4.3L engines



    Click image to see an enlarged view

    Fig. If access is difficult with the hose attached . . .



    Click image to see an enlarged view

    Fig. . . . remove the hose, then loosen and remove the housing retainers



    Click image to see an enlarged view

    Fig. Once the housing is free, carefully lift it from the engine to expose the thermostat



    Click image to see an enlarged view

    Fig. Sometimes, the thermostat will lift from the engine with the housing . . .



    Click image to see an enlarged view

    Fig. . . . but if not, note the direction it is installed, then lift if from the engine for replacement



    Click image to see an enlarged view

    Fig. Exploded view of the thermostat and housing assembly-4.3L engine

  10.  

To install:

  1. Tighten the thermostat housing-to-engine bolts or bolt and nut to 18 ft. lbs. (25 Nm).
  2.  
  3. Connect the battery cable, the properly refill and bleed the cooling system.
  4.  
  5. Run the engine and check for leaks.
  6.  

 
label.common.footer.alt.autozoneLogo