One mistake to avoid when using PTFE heat shrink tubing is attempting to apply it in locations which cannot withstand high temperatures. You can cause damage to other areas of the application or component, when you apply this tubing. You should always make sure to perform prior testing to check temperature stresses before directly applying this type of shrink tubing.
Apply PTFE Heat Shrink Tubing Externally for Components Sensitive to High Temperatures
Even in areas which are heat sensitive, you may still be able to use this type of tubing, by first removing the cable or wire. This will allow you to make repairs to the component or application, but avoid damaging it. Once the cable or wire has been removed, then you can apply the PTFE heat shrink tubing, externally. After the tubing is secure and cooled, then you can rerun the cable or wire back through the device or component.