Coolant Heat Shrink Hose Clamp

The 2019 Silverado 4500HD/5500HD/6500HD is equipped with the 6.6L Duramax diesel engine (RPO L5D). The engine uses heat shrink clamps to secure the engine coolant hoses. (Fig. 24)

If a coolant heat shrink clamp needs to be replaced for a coolant leak or a service repair, it may be difficult to reinstall a heat shrink clamp to seal the coolant hose in some locations. Where possible, a heat shrink clamp should be used in all places where they are installed.


Fig. 24


If there is a location underhood where it is difficult to get enough accessibility in order to use a heat gun to properly install the heat shrink clamp, use a hose clamp (part number 1518389C1) and torque the clamp to the proper specification (9-11 Nm or 79–97 lb. in.).

When installing a heat shrink clamp:

  1. Slide the heat shrink clamp fully over the fitting bead and as close to the hose end as possible. (Fig. 25)
  2. Turn heat shrink clamp so the writing on the clamp is fully visible.
  3. Set the heat gun to the high setting.
  4. Using the heat gun in a constant steady motion, apply heat to as much of the heat shrink clamp as possible.
  5. Continue heating the clamp until the printed information on the heat shrink clamp turns gray, indicating that enough heat has been applied.
  6. Stop heating the clamp.
  7. Check the quality of the seal by trying to turn the hose by hand. Neither the hose nor heat shrink clamp should turn.


Fig. 25


– Thanks to Bob Briedis



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  1. Mark Clothier says:

    Brilliant! GM engineering never ceases to amaze me! We have had very little problems with the clamps we use these days but that is about to change.

  2. this is great. hopefully the labour time will reflect extra procedures to remove ridiculous clamps

  3. The EL-38125–5A Ultra Torch Special Tool listed in SI should be used to remove the heat shrink clamp.

  4. Brian Lindsay says:

    this is great but how do you remove the clamp is it cut off or do you replace the hose ever time

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