Truck Cap Window Seal | Official ARE Replacement Part
Our window seal is the same factory-grade weatherstripping installed on every new ARE cap at the manufacturing line. This EPDM rubber seal creates a watertight barrier between glass and frame, blocking water intrusion and road noise while maintaining cabin temperature control. The extrusion profile matches original equipment dimensions exactly, so it seats into the glass channel without gaps or compression issues that plague generic aftermarket strips.
We engineer this seal for the full service life of your cap — UV-stabilized compound resists cracking in direct sun, while the closed-cell structure won’t absorb water or collapse under repeated door cycling. Whether you’re replacing worn weatherstripping on a ten-year-old DCU or installing glass in a custom side window project, this is the seal ARE installers use every day.
Weatherstripping specifications
Materials & Construction
We extrude this seal from ethylene propylene diene monomer rubber, the same material specified for automotive door seals and commercial building gaskets where long-term weathering resistance is critical. EPDM outperforms vinyl and neoprene in UV exposure — the carbon-black stabilizer package in our compound prevents surface chalking and maintains elastic memory through thousands of thermal cycles.
The bulb cross-section is a continuous extrusion with no splices or weak points along the run. Wall thickness measures 0.062 inches at the thinnest point, enough to seal against minor frame irregularities without tearing during installation. The hollow bulb compresses to roughly 60 percent of resting diameter under typical glass clamping pressure, creating contact force across the full perimeter without overstressing the mounting flange.
Measuring & Ordering
Measure the entire glass perimeter where seal contacts the frame — for a typical side slider that’s two vertical runs plus top and bottom rails. Add four inches to your total to account for corner miters and installation waste. We cut seals to order in one-foot increments, so round up to the nearest foot when placing your order.
The seal installs into a U-channel molded into ARE glass frames — you’ll see this channel as a continuous groove running the full perimeter of any factory window opening. For custom glass installations, verify your frame uses the standard 0.25-inch channel width before ordering. If you’re working on a cap with both sliding and fixed glass, the same seal profile works for all openings.
Installation & Fitment
Clean the glass channel with isopropyl alcohol to remove old adhesive residue and silicone. Start at a bottom corner and press the seal’s mounting flange into the channel, working six inches at a time to avoid stretching the rubber. The bulb should face outward toward the glass when properly seated — if it’s twisted inward, pull that section and reseat it.
At corners, cut the seal at a 45-degree miter and butt the ends together rather than overlapping. A small bead of silicone at each miter joint prevents water from wicking through the seam. The hardware you use to secure glass — whether cam locks or the spring clips found on older truck cap locking handle assemblies — compresses the seal bulb against the glass face, so you don’t need separate adhesive along the bulb itself. Once glass is installed, check for even compression all around by looking for a consistent contact shadow where bulb meets glass.
Essential ARE Truck Cap Parts & Hardware
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Window Seal Replacement Questions
A typical ARE side slider window requires 8 to 10 feet of seal depending on glass size. Measure the perimeter where the seal contacts the frame and add four inches for corner cuts and installation waste. We sell seal by the linear foot, so round up to the nearest whole foot when ordering.
Yes, as long as the glass was installed in the original ARE frame channel. Most aftermarket glass suppliers use the same perimeter dimensions as factory ARE glass, so the seal profile matches. If a previous owner installed metric glass with a different channel width, measure the existing seal’s bulb diameter before ordering.
Absolutely. The same extrusion works on side windows, front sliders, and rear barn doors across all ARE cap models. Barn doors typically have a larger perimeter, so measure the full opening and order enough linear feet to cover both door panels if your cap has a split rear opening.
The mounting flange press-fits into the ARE glass channel without adhesive for the primary bond. We recommend a small bead of silicone sealant at each corner miter joint to prevent water from wicking through the seam, but the seal itself stays in place from mechanical retention once the glass is clamped down.
Our EPDM seal is UV-stabilized for 10 to 15 years of outdoor exposure depending on climate. Caps in high-UV environments like the Southwest may see surface chalking after a decade, but the seal remains functional. Inspect annually for compression set — if the bulb no longer rebounds after you press it, that’s the signal to replace.
Yes. This is the identical extrusion we install on new caps during manufacturing. When you order ARE truck cap parts directly from us, you’re getting the exact component spec’d for your model — not a third-party substitute with slightly different dimensions or compound formulation.
EPDM remains elastic from -40°F to 250°F, which covers every climate condition a truck cap encounters. The seal won’t become brittle in northern winters or go soft in summer sun. That temperature stability is why we use EPDM instead of vinyl or neoprene for all ARE weatherstripping.