2 Piece Window Bus Glass For Peterbilt 379, 388, 389 #PFT-BG-379/389-RT
High Quality Bus Windshield Glass
Tinted On Bottom Of Glass
Rubber Seal And Lock Bead (Included)
Gives Old School Look
Spray Foam That Provides Shock Protection During The Shipping Process.
Sold As Pair
PETERBILT 389 / 379 BUS GLASS INSTALLATION INSTRUCTIONS
For first-time installs and replacements
1. Removing the Factory Peterbilt Glass
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Cut the inside molding all the way around.
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Apply slow, even pressure from the inside and push the glass outward until it releases.
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IMPORTANT:
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Remove all remaining butyl from the opening before installing the new bus-style glass.
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Do not leave any old adhesive behind — it will affect fitment.
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2. Removing Previously Installed Bus Glass (If Your Truck Already Has Bus Glass)
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Pull out the lock strip (chrome or black).
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Push the glass outward with light pressure until it comes free.
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Clean the rubber completely — remove all old sealant before reinstalling.
INSTALLATION OF 389 / 379 BUS GLASS
3. Preparing the Lock-Strip Rubber
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Install the lock-strip rubber onto the truck’s pinch weld.
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Position the seam at the center of the bottom of the frame.
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Rubber adjustment:
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If the glass does not sit tight, gently pull the rubber away from the corners to improve alignment.
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Minor stretching and adjusting is normal.
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IMPORTANT:
Use ONLY the lock-strip rubber supplied in the kit.
Other rubbers may cause the glass to fit incorrectly or not fit at all.
4. Installing the Glass Into the Rubber
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Spray the rubber with glass cleaner or silicone spray for lubrication.
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Set the bottom edge of the glass into the rubber channel first.
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Using a white stick or hook tool, work the rubber over the glass:
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Start at the bottom
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Move up each side
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Finish along the top
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CRITICAL SAFETY NOTE:
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Use steady, light pressure only.
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Do NOT push hard on the glass — bus glass will break with excessive force.
5. Final Seating and Inspection
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Once fully installed, massage the rubber around the entire perimeter:
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Rubber to glass
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Rubber to pinch weld
This ensures even, equal coverage on all four sides.
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6. Sealing
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Apply non-acidic silicone between:
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Rubber and glass
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Rubber and body
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Do not use acidic silicone — it can damage stainless and paint.
7. Installing the Lock Strip
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Install the black or chrome lock strip using a proper lock-strip tool.
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Make sure the lock strip snaps in fully for a tight seal.
8. Cleanup
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Remove excess silicone using:
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White sticks
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Razor blades (ONLY along the glass edge — never against painted surfaces)
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Wipe clean for a finished appearance.