How to Fix a Leaking Roof Rack

A leaking roof rack will cause damage to the interior of your vehicle. Over time, a leak will ruin the head liner, carpets, and seats. Fix a leak in the roof of a vehicle immediately after you notice itto avoid permanent damage. Holes drilled for mounting a roof rack should be waterproofed to prevent or fix a leak.Automobile adhesives and sealants are made for waterproofing and securing bolt and screw holes typical in a roof rack installation.

1. Remove all mounting hardware, including bolts and screws, from the cross-rails and stanchions, using a ratchet and screwdriver. Place all hardware in a can or bucket so you don't lose the pieces. Having the assembly instructions on hand will help with this process.

2. Wrap each bolt and screw with thread seal tape. This tape makes the bolts thicker while keeping the exact thread pattern of the hardware. Do not overwrap the threads or use tape that's damaged and wrinkled.

3. Clean the roof to remove dust and debris, using a rag. Dirt and grit will prevent a good seal on the mounting hardware.

4. Place a small amount of clear automotive silicone sealant on top of each mounting hole on the roof. A dime-size dollop or less will provide adequate waterproofing.

5. Replace the mounting brackets, and stanchions. Apply a bead of clear sealant to the underside of each bolt and screw head.

6. Place the bolts or screws in the proper holes and tighten them until they are hand-tight. To tighten all bolts and screws, turn them clockwise. Do not overtighten as this will damage the threads.

7. Reinstall the cross-rails, following the manufacturer's installation instructions.

Source: ehow.com