General Diagnosis
Customer InputOne of the most important factors in locating the source of body water leaks is customer input. The more information you receive from the customer, the easier it will be to determine the problem. Listed below are just a few general questions you could ask to get you going in the right direction.
1. Do you know where the water seems to come from?
2. When does the vehicle leak?
A. During a rainstorm?
B. When driving?
C. In a car wash?
D. Driving on a flooded street?
E. When parked on a hill?
3. Where is the water collecting?
After receiving as much information as possible from the customer, you can begin your diagnosis and testing.
Inspection
Before testing, look over the general area where the water seems to be coming in. Check for things that are obviously wrong, such as torn, loose, or badly distorted weatherstrips. Look for gaps and holes at body joints or corners that should be closed up or sealed. Even though the opening is not visible, traces of rust can be a sign of an open body seam. Sometimes you can locate a water leak by examining the door opening surfaces, especially after the vehicle has been driven in wet weather. Look at the dried road splash around the area outside the weatherstrip contact line. If the weatherstrip is sealing properly, there will not be any trace of splash inside the line.
Inspection (continued)
When inspecting for visible water leaks, be sure to check the alignment of the doors to see how well they fit in the opening. As with doors, checking the obvious also applies to deck lids and hatches. Here again, proper alignment and closing are basic requirements for good weatherstrip sealing, especially when the vehicle has had body repairs or glass replacement that may result in component misalignment.
When inspecting for a floor pan water leak, traces of mud or dirt are an indication that the water is coming in from below. Still, it is possible for water to enter higher up and run downward to soak the carpet.
Water Testing Notes
Other tests can be used for checking sealing and leaking, but water is the only practical test for leaks around the windshield, rear window, inner door panel watershields, body joints and seams.
Figure 1:
Only a small stream of water is needed to find a leak (Figure 1). If too much water is used, it can be forced past even a good fitting weatherstrip. It can also splash over the suspected area, so you will have trouble finding the leak source.
The actual test is easy. Remove the hose spray nozzle and restrict the flow enough to get about a three inch stream.
NOTE: The water may rush out when first turned on, point the hose away from the test area to prevent overwetting.
Recommended Sealants
In the text that follows you will read references to sealing materials. Any high quality sealant that is right for the application will be acceptable. Three such sealants are shown in the table below.
SEALANT RECOMMENDATIONS
3M Part No.08634 Window Weld Resealant
or equivalent
3M Part No.08648 Joint and Seam Sealer
or equivalent
3M Part No.08655 Brushable Seam Sealer
or equivalent