Ram B1500, B2500, B3500, 1999-2003

Removal & Installation

Print


CAUTION
Do not loosen the radiator draincock with the system hot and pressurized. serious burns from the coolant can occur.

Do not waste reusable coolant. If the solution is clean, drain the coolant into a clean container for reuse.

  1. Disconnect the battery negative cables.
  2.  
  3. Drain cooling system until coolant level is below thermostat
    WARNING
    Constant tension hose clamps are used on most cooling system hoses. When removing or installing, use only tools designed for servicing this type of clamp, such as special clamp tool (number 6094).


    WARNING
    A number or letter is stamped into the tongue of constant tension clamps. If replacement is necessary, use only an original equipment clamp with a matching number or letter.

  4.  
  5. Remove radiator hose clamp and hose from thermostat housing (1).
  6.  
  7. Remove the three water outlet-to-cylinder head bolts and remove the water outlet connector .
  8.  
  9. Clean the mating surfaces of the water outlet connector and clean the thermostat seat groove at the top of the thermostat housing .

    Click image to see an enlarged view

    Fig. Exploded view of the thermostat housing (1), cylinder head (2) and thermostat (3)-5.9L diesel engine

  10.  

To install:

  1. Inspect thermostat seal for cuts or nicks. Replace if damaged.
  2.  
  3. Install the thermostat into the groove in the top of the cylinder head (2).
  4.  
  5. Install the thermostat housing (1) and bolts. Tighten the bolts to 89 inch lbs. (10 Nm).
  6.  
  7. Install the radiator upper hose and clamp.
  8.  
  9. Fill the cooling system with coolant.
  10.  
  11. Connect the battery negative cables.
  12.  
  13. Start the engine and check for coolant leaks. Run engine to check for proper thermostat operation.
  14.  


CAUTION
Do not loosen the radiator draincock or cap with the system hot and pressurized. serious burns from the coolant can occur.

Do not waste reusable coolant. If the solution is clean, drain the coolant into a clean container for reuse. If the thermostat is being replaced, be sure that the replacement is the specified thermostat for the vehicle model and engine type. Factory installed thermostat housings on all engines are installed on a gasket with an anti-stick coating. This will aid in gasket removal and clean-up.

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the cooling system until coolant level is below thermostat.
    1. If equipped with air conditioning, perform the following:
    2.  
    3. Remove engine cover from vehicle interior.
    4.  
    5. Remove the support bracket (generator mounting bracket-to-intake manifold) located near the rear of generator.
    6.  
    7. The generator must be partially removed. Remove the accessory drive belt.
    8.  
    9. Remove the two generator mounting bolts. Do not remove any wiring at generator.
    10.  
    11. Remove generator. Position generator to gain access for thermostat gasket removal.
    12.  
    13. Remove the three Powertrain Control Module (PCM) mounting bolts and remove PCM. Do NOT disconnect the 60-way connector from PCM. Position the PCM safely aside.
      WARNING
      Constant tension hose clamps are used on most cooling system hoses. when removing or installing, use only tools designed for servicing this type of clamp, such as special clamp tool (number 6094). Snap-On® clamp tool (Number HPC-20) may be used for larger clamps. always wear safety glasses when servicing constant tension clamps.


      NOTE
      A number or letter is stamped into the tongue of constant tension clamps. If replacement is necessary, use only an original equipment clamp with matching number or letter.

    14.  

  4.  
  5. Remove upper radiator hose clamp. Remove upper radiator hose at thermostat housing.
  6.  
  7. Position the wiring harness (behind the thermostat housing) to gain access to thermostat housing.
  8.  
  9. Remove thermostat housing mounting bolts, thermostat housing, gasket and thermostat. Discard old gasket.
    WARNING
    Never use abrasive cleaning products such as wire brushes or metal scrapers to remove gasket material. Severe damage can occur to thermostat housing sealing surfaces.

  10.  

To install:

Click image to see an enlarged view

Fig. View of the thermostat housing (1), gasket (2), intake manifold (3), thermostat (4), machined groove (5)

  1. Install thermostat (spring side down) into recessed machined groove on intake manifold .
  2.  
  3. Install gasket on intake manifold and over thermostat .
  4.  
  5. Position the thermostat housing to the intake manifold. Note the word FRONT stamped on the housing. For adequate clearance, this must be placed towards the front of vehicle. The housing should be slightly angled forward after installation to intake manifold.
  6.  
  7. Install two housing-to-intake manifold bolts. Tighten the bolts to 18 ft. lbs. (24 Nm).
    WARNING
    The housing must be tightened evenly and thermostat must be centered into recessed groove in intake manifold. If not, it may result in a cracked housing, damaged intake manifold threads or coolant leak.

  8.  
  9. Install upper radiator hose to thermostat housing.
  10.  
  11. For vehicles with air conditioning, perform the following:
    1. Install generator. Tighten the bolts to 30 ft. lbs. (41 Nm.
    2.  
    3. Install support bracket (generator mounting bracket-to-intake manifold). Tighten bolts to 40 ft. lbs. (54 Nm).
      WARNING
      When installing the serpentine accessory drive belt, the belt must be routed correctly. If not, the engine may overheat due to the water pump rotating in the wrong direction. Refer to Accessory Drive Belt Routing for correct engine belt routing. The correct belt with the correct length must be used.

    4.  
    5. Install accessory drive belt
    6.  
    7. Install PCM.
    8.  

  12.  
  13. Fill cooling system.
  14.  
  15. Connect battery negative cable.
  16.  
  17. Start and warm engine. Check for leaks.
  18.  
  19. Install engine cover (if equipped with A/C).
  20.  


WARNING
Most cooling system hoses use "constant tension" hose clamps. When removing or installing, use a tool designed for servicing this type of clamp. The clamps are stamped with a letter or number on the tongue. If replacement is necessary, use only an OEM clamp with a matching ID.


CAUTION
Always wear safety glasses when servicing contact tension clamps.

  1. Locate the thermostat. This is located in a housing on the engine side of the upper radiator hose for all engines except the 4.7L. On the 4.7L engine, the thermostat is located on the engine side of the lower radiator hose.
  2.  
  3. Disconnect the negative battery cable (both batteries on diesels).
  4.  
  5. Drain the engine coolant from the block until the level is below the thermostat.
  6.  
  7. On V-10 engines, remove the support rod.
  8.  
  9. On most V-6 and V-8 models, the alternator must be removed or repositioned for access to the thermostat housing.
  10.  
  11. Remove the radiator hose from the thermostat housing.
  12.  
  13. Disconnect any sensors fitted to the thermostat housing.
  14.  
  15. Remove the retaining bolts from the thermostat housing. Note the lengths and location of each bolt for ease of installation.
  16.  
  17. Remove the thermostat housing, thermostat, and gasket, if fitted.
  18.  
  19. Note the relative positions of all components, especially gaskets and seals. Note the orientation of the thermostat in the housing.
  20.  

To install:

  1. Be sure the new thermostat is the correct one for your engine.
  2.  
  3. On V-10 engines, note that there is a rubber lip-type seal with a metal shoulder pressed into the intake manifold beneath the thermostat. The thermostat should fit snugly in the seal.
  4.  
  5. Clean the gasket or seal mating surfaces.
  6.  
  7. Paper gaskets must be replaced.
  8.  
  9. Install the thermostat, gasket or seals.
  10.  
  11. Install the thermostat housing on the engine.
  12.  


NOTE
The thermostat housing may have the word FRONT on it (3.9L, 5.2L, 5.9L); this goes towards the front of the vehicle.

  1. Be sure all components are properly seated before tightening.
  2.  
  3. Tighten the housing bolts to 18 ft. lbs. (24 Nm). Fasteners should be tightened evenly to avoid leaks or damage.
  4.  
  5. Reinstall the radiator hose onto the housing.
  6.  


NOTE
Ensure that you have secured the system drain plug(s) before refilling with coolant.

  1. Refill the radiator with a proper coolant mixture.
  2.  
  3. Connect the negative battery cable(s).
  4.  
  5. Start the engine and bleed the cooling system. Refer to "GENERAL INFORMATION AND MAINTENANCE."
  6.  
  7. Ensure that the thermostat is operational (by checking the upper radiator hose for warmth), and that there are no leaks.
  8.  



Click image to see an enlarged view

Fig. Safe removal of constant tension clamps requires the proper tool



Click image to see an enlarged view

Fig. Thermostat assembly (2.5L). Note bolt lengths and locations



Click image to see an enlarged view

Fig. On 3.9L, 5.2L, and 5.9L (gas) engines, the gasket goes above the thermostat



Click image to see an enlarged view

Fig. On the 4.7L engine, the thermostat is at the bottom of the engine



Click image to see an enlarged view

Fig. V-10 thermostat assembly



Click image to see an enlarged view

Fig. The diesel thermostat has two seals-1997-99 models



Click image to see an enlarged view

Fig. Late model diesel thermostat assembly-2000 models



Click image to see an enlarged view

Fig. Removing the thermostat from the manifold-typical



Click image to see an enlarged view

Fig. A bit of paper towel will keep the bolt in the socket until the bolt hole is reached

3.7L & 4.7L Engines




CAUTION
Do not loosen the radiator draincock with the cooling system hot and pressurized. Serious burns from the coolant can occur.

Do not waste reusable coolant. If the solution is clean, drain the coolant into a clean container for reuse.

If the thermostat is being replaced, be sure that the replacement is the specified thermostat for the vehicle model and engine type.

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the cooling system.
  4.  
  5. Raise and support the vehicle.
  6.  
  7. Remove the splash shield.
  8.  
  9. Remove the lower radiator hose clamp and the lower radiator hose at the thermostat housing.
  10.  
  11. Remove the thermostat housing mounting bolts, thermostat housing and thermostat.

    Click image to see an enlarged view

    Fig. Location of the thermostat (2), thermostat housing (1), thermostat & gasket (3) and timing chain cover (4)-3.7L & 4.7L engines

  12.  

To install:

  1. Clean the mating areas of the timing chain cover and the thermostat housing.
  2.  
  3. Install the thermostat (spring side down) into the recessed machined groove on the timing chain cover.
  4.  
  5. Position the thermostat housing on the timing chain cover.
  6.  
  7. Install the housing-to-timing chain cover bolts. Tighten the bolts to 112 inch lbs. (13 Nm).
    WARNING
    The housing must be tightened evenly and the thermostat must be centered into the recessed groove in the timing chain cover. If not, it may result in a cracked housing, damaged timing chain cover threads or coolant leaks.

  8.  
  9. Install the lower radiator hose on the thermostat housing.
  10.  
  11. Install the splash shield.
  12.  
  13. Lower the vehicle.
  14.  
  15. Fill the cooling system.
  16.  
  17. Connect negative battery cable. Start and warm the engine. Check for leaks.
  18.  

3.9L & 5.9L Engines




CAUTION
Do not loosen radiator draincock with system hot and pressurized. serious burns from coolant can occur.

Do not waste reusable coolant. If solution is clean, drain coolant into a clean container for reuse. If thermostat is being replaced, be sure that replacement is specified thermostat for vehicle model and engine type.

Factory installed thermostat housings on 3.9L, 5.2L and 5.9L engines are installed on a gasket with an anti-stick coating. This will aid in gasket removal and clean-up.

  1. Disconnect the negative battery cable.
  2.  
  3. Drain cooling system until coolant level is below thermostat.
  4.  
  5. On vehicles with A/C, remove support bracket (generator mounting bracket-to-intake manifold) located near rear of generator.
    NOTE
    On vehicles with A/C, the generator must be partially removed.

  6.  
  7. Remove accessory drive belt, as outlined in this section.
  8.  
  9. Remove two generator mounting bolts. Do not remove any wiring at generator. If equipped with 4WD, unplug 4WD indicator lamp wiring harness (located near rear of generator).
  10.  
  11. Remove generator. Position generator to gain access for thermostat gasket removal.
    CAUTION
    Constant tension hose clamps are used on most cooling system hoses. When removing or installing, use only tools designed for servicing this type of clamp, such as special clamp tool (number 6094). Snap-on clamp tool (number hpc-20) may be used for larger clamps. Always wear safety glasses when servicing constant tension clamps.


    WARNING
    A number or letter is stamped into the tongue of constant tension clamps. If replacement is necessary, use only an original equipment clamp with matching number or letter.

  12.  
  13. Remove radiator upper hose clamp and upper hose at thermostat housing.
  14.  
  15. Position wiring harness (behind thermostat housing) to gain access to thermostat housing.
  16.  
  17. Remove thermostat housing mounting bolts, thermostat housing, gasket and thermostat. Discard old gasket.
  18.  
  19. Clean mating areas of intake manifold and thermostat housing.

    Click image to see an enlarged view

    Fig. Safe removal of constant tension clamps requires the proper tool



    Click image to see an enlarged view

    Fig. On 3.9L, 5.2L, and 5.9L (gas) engines, the gasket goes above the thermostat

  20.  

To install:

  1. Install thermostat (spring side down) into recessed machined groove on intake manifold.
  2.  
  3. Install gasket on intake manifold and over thermostat.
  4.  
  5. Position thermostat housing to intake manifold. Note the word FRONT stamped on housing. For adequate clearance, this must be placed towards front of vehicle. The housing is slightly angled forward after installation to intake manifold.
  6.  
  7. Install two housing-to-intake manifold bolts. Tighten bolts to 17 ft. lbs. (23 Nm).
  8.  
  9. Install radiator upper hose to thermostat housing.
    WARNING
    When installing the serpentine accessory drive belt, the belt must be routed correctly. If not, engine may overheat due to water pump rotating in wrong direction. Refer to Belts in this section for correct 3.9L, 5.2L and 5.9L engine belt routing. The correct belt with correct length must be used.

  10.  
  11. For vehicles with A/C, install generator and tighten the bolts to 30 ft. lbs. (40 Nm).
  12.  
  13. Install support bracket (generator mounting bracket-to-intake manifold). Tighten the bolts to 40 ft. lbs. (54 Nm).
  14.  
  15. Install accessory drive belt.
  16.  
  17. Fill cooling system.
  18.  
  19. Connect the negative battery cable.
  20.  
  21. Start and warm the engine. Check for leaks.
  22.  

5.7L Engines




CAUTION
Do not loosen the radiator draincock with the cooling system hot and pressurized. serious burns from the coolant can occur.

Do not waste reusable coolant. If the solution is clean, drain the coolant into a clean container for reuse.

If the thermostat is being replaced, be sure that the replacement is the specified thermostat for the vehicle model and engine type.

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the cooling system
  4.  
  5. Remove the radiator hose clamp and radiator hose at the thermostat housing.
  6.  
  7. Remove the thermostat housing mounting bolts, thermostat housing and thermostat .

    Click image to see an enlarged view

    Fig. View of the retaining bolt (1), thermostat housing (2), clamp (3) and radiator hose (4)-5.7L engine

  8.  

To install:

  1. Position the thermostat and housing on the front cover.
  2.  
  3. Install thermostat housing bolts. Tighten the bolts to 112 inch lbs. (13 Nm).
  4.  
  5. Install the radiator hose onto the thermostat housing.
  6.  
  7. Fill the cooling system.
  8.  
  9. Connect negative battery cable.
  10.  
  11. Start and warm the engine. Check for leaks.
  12.  

8.0L Engine




CAUTION
Do not loosen the radiator draincock with the system hot and pressurized. Serious burns from the coolant can occur.

Do not waste reusable coolant. If the solution is clean, drain the coolant into a clean container for reuse. If the thermostat is being replaced, be sure that the replacement is the specified thermostat for the vehicle model and engine type.

A rubber lip-type seal with a metal shoulder is pressed into the intake manifold beneath the thermostat.

  1. Disconnect the negative battery cable.
  2.  
  3. Drain cooling system until coolant level is below thermostat.
  4.  
  5. Remove the two support rod mounting bolts and remove support rod (intake manifold-to-generator mount).
    CAUTION
    Constant tension hose clamps are used on most cooling system hoses. When removing or installing, use only tools designed for servicing this type of clamp, such as special clamp tool (number 6094). Snap-on clamp tool (number hpc-20) may be used for larger clamps. Always wear safety glasses when servicing constant tension clamps.


    WARNING
    A number or letter is stamped into the tongue of constant tension clamps . If replacement is necessary, use only an original equipment clamp with a matching number or letter.

  6.  
  7. Remove upper radiator hose clamp. Remove upper radiator hose at thermostat housing.
  8.  
  9. Disconnect the wiring connectors at both of the sensors located on thermostat housing.
  10.  
  11. Remove six thermostat housing mounting bolts, thermostat housing and thermostat.
  12.  
  13. Clean mating areas of intake manifold and thermostat housing.
  14.  
  15. Check the condition (for tears or cracks) of the rubber thermostat seal located in the intake manifold. The thermostat should fit snugly into the rubber seal.

    Click image to see an enlarged view

    Fig. 8.0L V-10 thermostat assembly

  16.  

To install:

  1. If seal replacement is necessary, coat the outer (metal) portion of the seal with Mopar®Gasket Maker. Install the seal into the manifold using Special Seal Tool number C-3995-A with handle tool number C-4171.
  2.  
  3. Install thermostat into recessed machined groove on intake manifold.
  4.  
  5. Install thermostat housing.
  6.  
  7. Install housing-to-intake manifold bolts. Tighten bolts to 18 ft. lbs. (25 Nm).
    WARNING
    Housing bolts should be tightened evenly to prevent damage to housing and to prevent leaks.

  8.  
  9. Connect the wiring to both sensors.
  10.  
  11. Install the upper radiator hose and hose clamp to thermostat housing.
  12.  
  13. Install support rod.
  14.  
  15. Fill cooling system.
  16.  
  17. Connect the negative battery cable.
  18.  
  19. Start and warm engine. Check for leaks.
  20.  

 
label.common.footer.alt.autozoneLogo