Article 925 - Windshield and Backlite Water Leaks

TSB #49 - November 4, 1966
(All 1965-66-67 Models Having Butyl Tape Installed Glass)


Windshield and backlite water leaks on 1965-66-67 models having butyl tape installed windshield and backlite do not require removal of the glass to correct a water leak. The proper application of an approved liquid butyl sealer such as C5AZ-19554-A, will adequately seal all butyl to glass and butyl to sheet metal water leaks.

Whenever a water leak is encountered on windshield or backlite using butyl tape, the vehicle should be tested with water or air pressure to identify the leak area. If the leak is in the windshield or backlite areas, the exterior chrome mouldings should be removed and the leak area sealed by use of an approved liquid butyl. Not all water leaks in the windshield and backlite area are attributable to the butyl seal. Other items which may be the cause of the leak are as follows:
  • Sheet metal joints — Sheet metal joint outboard of the butyl seal should be inspected to insure that sealer skips or voids, or sheet metal defects such as weld burn through holes are corrected.
  • Moulding retainers — Normally, the moulding retainers are secured with a weld stud. Whenever the retention of the weld stud is inadequate, a sheet metal screw is utilized to secure the retainer. These areas should be inspected to insure that the weld stud hole is sealed and that the hole for the retainer screw is also sealed.
  • "A" Pillar mouldings - On some models water wicks under the "A" pillar moulding and under the roof rail weatherstrip retainer resulting in a leak in the "A" pillar area which might mistakenly be diagnosed as a windshield leak. On these vehicles, the "A" pillar moulding should be removed and a bead of sealer should be applied between the moulding and the back face of the "A" pillar.
  • Convertible header moulding — Frequent windshield leaks are due to an inadequate seal between the header moulding and the header sheet metal on convertible models. These leaks should be corrected by adding additional sealer between the header moulding and the header sheet metal.
The C5AZ-19554-A sealer has the ability to flow into areas where sealer was omitted; it is not necessary to remove the glass to correct the water leak.

After the repair has been completed, the liquid butyl should be permitted to dry. A re-test should then be conducted to determine if the repair performed corrected the leak area.