Centinel System – Repair Manual – 008-080   Belt Tensioner, Automatic (Water Pump)

With the engine turned off and with the water pump/fan belt installed, check that neither the top nor bottom tensioner arm stop is touching the cast boss on the tensioner body. If either of the stops is touching a boss, the water pump/fan belt must be replaced. Check to make sure the correct belt part number is being used if either condition exists.

Check the tensioner pulley and body for cracks. If any cracks are noticed, the tensioner must be replaced.

Using a ½ inch square drive, lift belt tensioner to relieve tension on the belt.

Remove the water pump/fan belt.

The belt tensioner is spring-loaded and must be pivoted away from the drive belt. Pivoting in the wrong direction can result in damage to the belt tensioner.

If the tensioner pulley touches the accessory drive pulley after the tensioner has been fully relaxed, the bottom tensioner arm stop boss has broken and the tensioner must be replaced.

Make sure the bottom tensioner arm stop is in contact with the bottom tensioner arm stop boss on the tensioner body.

If these two are not contacting, the tensioner must be replaced.

CAUTION  The belt tensioner is spring loaded and must be pivoted away from the drive belt. Pivoting in the wrong direction can result in damage to the belt tensioner or personal injury.

• Remove the cooling fan belt. Refer to Procedure 008-002.

Remove the mounting capscrew and the belt tensioner from the bracket.

NOTE: Different engine configurations utilize different belt tensioner bracket and belt tensioner arrangements.

For the low-mount belt tensioner:

Remove the belt tensioner mounting capscrew and belt tensioner from the bracket.

Remove the belt tensioner bracket from the water pump.

For the mid-mount belt tensioner:

Remove the belt tensioner mounting capscrew and the belt tensioner from the bracket.

The mid-mount aluminum belt tensioner/idler bracket is part of the water pump removal and installation because of common capscrew usage. Refer to Procedure 008-062.

For the low-mount (small version) belt tensioner:

Remove the belt tensioner mounting capscrew and belt tensioner from the bracket.

Remove the belt tensioner bracket from the front engine support.

For the low-mount (large version) belt tensioner:

Remove the belt tensioner mounting capscrew and belt tensioner from the bracket.

Remove the belt tensioner bracket from the front engine support.

WARNING  The belt tensioner is spring loaded. Do not attempt to disassemble the tensioner. Severe personal injury can result.

WARNING  When using solvents, acids or alkaline materials for cleaning, follow the manufacturers recommendations for use. Wear goggles and protective clothing to reduce the possibility of personal injury.

Check the tensioner for dirt buildup. If the tensioner has dirt buildup, remove and clean with safety solvent.

Pivot the tensioner through the full range of motion. Tensioner must move with resistance while pivoting the tensioner down. If not, replace the tensioner.

Check and make sure the correct belt part number is being used.

Check the belt tensioner pulley and body for cracks or damage. If any are found, replace the tensioner.

Inspect the tensioner arm stop bosses, for cracks or damage. If cracks or damage is found, replace the tensioner.

Spin the tensioner pulley. If pulley does not spin freely, replace the tensioner.

WARNING  When using a steam cleaner, wear safety glasses or a face shield, as well as protective clothing. Hot steam can cause serious personal injury.

Check the tensioner for dirt buildup. If this condition exists, the tensioner must be removed and steam-cleaned.

Inspect the tensioner for evidence of the pivoting tensioner arm contacting the stationary circular base. If there is evidence of these two areas contacting, the pivot tube bushing has failed and the tensioner must be replaced.

Install the belt tensioner and mounting capscrew.

Tighten the capscrew.

For the low-mount belt tensioner:

Install the belt tensioner bracket to the water pump.

Tighten capscrew.

Install the belt tensioner and capscrew.

For the mid-mount belt tensioner:

Install the belt tensioner mounting capscrew and the belt tensioner from the bracket.

The mid-mount aluminum belt tensioner/idler bracket is part of the water pump removal and installation due to common capscrew usage. Refer to Procedure 008-062.

For the low-mount (small tensioner):

Install the belt tensioner bracket to the front engine support with three mounting capscrews.

Install the belt tensioner.

For the low-mount (large tensioner):

Install the belt tensioner bracket to the front engine support with three mounting capscrews.

Install the belt tensioner.

CAUTION  The belt tensioner is spring loaded and must be pivoted away from the drive belt. Pivoting in the wrong direction can result in damage to the belt tensioner or personal injury.

• Install the drive belt. Refer to Procedure 008-002.