Practical Execution Of Tests And Checks

Compressed air test 

Courtesy of JAGUAR LAND ROVER NORTH AMERICA, LLC

• Lower the headliner at the front of the vehicle to give clear access to the upper section of the windshield inside the vehicle.
• The leak may be located behind the exterior A-pillar windshield mouldings (if installed), so these should be removed before commencing testing Make sure the windshield moulding carrier remains installed  as this may be a source of the water leak and should be in situ for the tests as described below.
• On the outside of the vehicle, use a hand-held spray-bottle to apply a fine mist of soapy water to the areas all around the exterior windshield edge joints (see image A above - Note: image is NOT vehicle specific).
• From the inside of the vehicle, use an air hose to blow a jet of compressed air around the interior windshield edge joints.
• The leak should be located from outside by a second assistant. Bubbles will form in the affected area and escaping air may be audible (see image B above - Note: image is NOT vehicle specific).
• Take a photograph of the vehicle showing the location of the water ingress point(s) before proceeding. Make sure that an image is attached to an Electronic Product Quality Report (EPQR) before proceeding with any windshield removals.
• When the leak point(s) have been noted, remove the windshield.
  NOTE: Depending on the nature of the leak point, it may be possible to reuse the windshield

  Consequently, make sure the correct equipment and procedures are utilized during removal of the windshield.

• When the windshield has been removed from the vehicle, it is important to confirm the specific nature of the leak. The image below shows a representation (not to scale) of the materials involved when a windshield is installed. A layer of primer is applied to the windshield glass; a layer of adhesive is applied; finally, the windshield is mounted into the frame. Consequently, there are two possible entry points for water ingress:
  • Water ingress between the windshield adhesive layer and the windshield glass (see arrow A, below)
  • Water ingress between the vehicle body and the windshield adhesive layer (see arrow B, below)
• Where possible, note the specific nature of the water ingress (as specified above). Photograph the leak point and attach both the photo and a written description of the location and nature of the water ingress/leak point to the EPQR  .
• If the leak point is identified as being between the vehicle body and the windshield adhesive layer, the existing windshield may be re-used  . Thoroughly remove all traces of adhesive and primer from the existing windshield, clean the windshield and refit.
• If the leak point is identified as being between the windshield adhesive layer and the windshield glass, the existing windshield should be replaced and a new windshield installed.

Courtesy of JAGUAR LAND ROVER NORTH AMERICA, LLC

Water test 

• Complete the water test with a second person present (in the passenger compartment).
• Use variable washer nozzles (concentrated water jet to fine spray mist).
• Lower the headliner at the front of the vehicle to give clear access to the upper section of the windshield inside the vehicle.
• The outer trims must be raised carefully using a plastic wedge.
• Start in the lower section and spray the whole area, working upwards in stages.
• The leak should be located from inside by a second assistant.

Washer test 

• Further tests can be completed in the washer system.
• Some leaks originate here, or only occur here.
• The relevant passenger compartment should be checked using a flashlight during the wash procedure.

Road test 

• If no leaks are located during the tests above, road tests should be completed on wet roads.
• Road tests under various conditions:
  • At various speeds.
  • On various road surfaces (asphalt to cobbles).
  • With loaded or unloaded vehicle.
  • Driving through puddles (splash water).

Other test equipment 

• Other equipment such as stethoscopes, ultraviolet (UV) lamps, special mirrors or ultrasound measuring instruments can be used to locate leaks.