ISSUE DATE:
REVISION DATE:
SERVICE BULLETIN SUBJECT:
VINs or MODELS AFFECTED:
COMPLETE BY:
SERVICE BULLETIN #:

6/29/2020
7-13-2022
Side Window Seal Retrofit
Service Specified Buses
Next Service Opportunity
SB-20-85

SIDE WINDOW SEAL RETROFIT
NOTICE! It is expected that this process will require 4 hours per bus. Please
schedule appropriately to minimize vehicle downtime.

Retrofit Description:

This retrofit adds improved window seals to prevent water intrusion into the bus.

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

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Tools/Parts Required
Tools and Supplies Required:
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•
•
•
•
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Suction Cups
T-20 Torx Bit
Drill Driver
Masking Tape
Permanent Marker
Calibrated Torque Wrench
Putty Knife
Approved Safety Knife

Parts Required:
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•
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051506
017093
016103

SEAL, SIDE WINDOWS
170 FT
SCREW, #10 TORX PH, #8 HD, TEK, 410 SS, BLK OX, 1" 334 EA
SEALANT, BUTYL, NON-HARDENING
1 EA

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

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Procedure:
1. Complete the Proterra approved Lockout/Tagout procedure to make the bus safe for work.
2. On the interior of the bus, remove the side window trim (031241) that covers the fasteners
securing the side window in place and mark the trim location using tape and a marker.
3. On the interior of the bus and working one window at a time, using a T-20 Torx Bit and Drill
Driver, remove all Torx screws securing the side window.
IMPORTANT! Ensure the exterior window glass and frame are properly supported on the
exterior of the vehicle, using suction cups, prior to removing all the Torx screws.

4. Carefully place the window in a suitable location for installing the new Seal (051506).
5. Using a Putty Knife, carefully remove the old outer seal from the window frame.

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

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6. Using Shop Towels and Isopropyl Alcohol, remove any leftover seal residue from the window
frame and clean the surfaces of the frame.
7. Using an approved Safety Knife, cut the new Seal (051506) to the correct length to fit the
window.
8. Carefully peel the Adhesive Backing off the new Seal (051506).
9. Starting at the bottom of the window, press the adhesive side of the Seal (051506) to the
window frame. Continue around the window frame to attach the remaining portion of the Seal
to the frame.
10. Using an approved Safety Knife, carefully trim the Seal (051506) so that the two ends meet at
the bottom of the window. Try to leave the least amount of gap as possible between the ends
of the seal as shown below.

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

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11. Using a Putty Knife, prep the window portal for reinstalling the window by removing the Butyl
Sealant from the portal as shown in the following photographs.

12. Using Alcohol and Shop Towels, clean the portal.
13. Apply new Butyl Sealant (016103) to the Seal (051506).
14. Carefully place the window with the new Seal (051506) back into the window portal.
15. With the window properly positioned in the portal, using a T-20 Torx Bit and Drill Driver, install
and hand tighten all new Torx Screws (017093) securing the side window.
IMPORTANT! Ensure the exterior window glass and frame are properly supported on the
exterior of the vehicle, using suction cups, while installing all the Torx screws.

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

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16. Following the torque pattern shown below, torque each of the Torx Screws (017093) to 40
Inch Pounds.

17. Verify window trim position and then reinstall the interior window trim that covers the fasteners.
18. Repeat this procedure for all side windows.
19. When the Seals (051506) have been replaced on all windows, remove the Lockout/Tagout
devices and return the bus to service.

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

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