My “84 Chevrolet pickup leaks water – it’s clear in color so I know it’s not coolant or from the air conditioner – into the cab whenever it rains or I wash it. A small quantity ends up on the driver’s side floor and an even larger amount on the passenger side. Could it be from the windshield seal, or somewhere else? How bad is this going to hurt to fix?

Soggy in Salinas

Dear Soggy, you have my empathy. The smell of wet carpet is a lousy way to start your morning commute, and the day to follow.

Let’s perform a couple of inspections and then pick the best course of action.

Start by checking the exterior of the windshield rubber seal for shrinkage, cracking or other visible faults.

Next, with the hood open, carefully inspect the cowl – the metal housing just below the base of the windshield – for rust perforations or dried out/receded sealer on its many seams and junctions. At this time you may want to clean then reseal any questionable areas with a bead of household exterior latex sealer, such as Alex.

After allowing sufficient cure time for the sealer, recruit a helper and try to determine the general area of the likely remaining leak(s). While lying inverted, head by the pedals (and then again on the passenger side), have your helper apply water from the hose in a gentle, flooding manner back and forth across the cowl area, but not higher. Can you see evidence of the water entering?

Perhaps from above the pedals, trickling down the front edge of the door jamb, or dripping from the plastic trim panel behind the parking brake pedal? On the passenger side, also check for dripping from the base of the heater box.

If leakage is noted, the fault might lie in the more difficult-to-access cowl seams in the kick panel area (just ahead of the doors) or in the area beneath the ventilation intake screen.

If not, instruct your helper to next flood the windshield seal, starting at its lower edge, progressing slowly higher. Try to note the time of leakage as soon as possible, and call to your helper to concentrate on that particular area.

Removal of the windshield pillar trim and/or dashboard pad will allow a better view of the exact entrance point of the water.

My hunch is you’ll find leakage from the cowl in the kick panel area. Chevy trucks of this vintage were built to accommodate kick panel vents, when not equipped with A/C. This area – behind the triangular plastic trim panel – is vulnerable to leakage due to lousy spot welds and ill-fitting seams.

Removing the trim panels will allow a more detailed inspection during water testing, and provides access for seam resealing. Small rusted areas may be patched with cut-to-shape plastic inserts, bonded by sealer.

If you’re up for a little disassembly and diligent sealer application, repairing the cowl seams is within the ability of a home mechanic.

The windshield seal or advanced rust issues I would save for a professional.

Brad Bergholdt is an automotive technology instructor at Evergreen Valley College in San Jose.

Write to him in care of Drive, Mercury News, 750 Ridder Park Drive, San Jose, Calif. 95190; or e-mail to under-the-hoodjuno.com. He cannot make personal replies.)

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AP-NY-09-09-05 0618EDT