Convertible Top Hydraulic Fluid: Service and Repair
Folding Top Fluid Addition
Caution:
Always put an automatic transmission in P (Park) or a manual transmission in N (Neutral) and set the park brake before raising or lowering the convertible top. If you raise or lower the convertible top while the vehicle is in motion, you could damage the top or the top mechanism.
Caution:
Do not lower the top in cold weather. If you lower the convertible top on the vehicle in cold weather (0°C (32°F) or lower), you may damage convertible top components.
Caution:
Always verify that no objects are in the storage area before lowering the convertible top. Lowering the convertible top when there are objects in the storage area could damage it or break the glass rear window.
Caution:
Dry off the convertible top before lowering it. Lowering the convertible top if it is damp, wet, or dirty can cause stains, mildew, and damage to the inside of the vehicle.
Check Fluid Level
1. When servicing the hydraulic system do not allow the fluid level to drop below the minimum indicator line on the reservoir. The Rear Seat Back and Insulator pad must be removed to view the level mark on the reservoir. Refer to Rear Seat Back Cushion Pad Replacement Rear Seat Back Cushion Pad Replacement.
2. Inspect the hydraulic fluid level with the vehicle parked on a level surface, the folding top in the closed position.
3. Use only approved hydraulic fluid for Hydraulic Folding Top Pump GM P/N 88901975, fluid should be green in color.
4. When new, the power folding top hydraulic fluid is golden clear. As the system is cycled, it picks up the carbon black from the numerous O-ring seals used in the system. The carbon black acts like a dye and causes the fluid to darken considerably and take on a black appearance. This is a normal occurrence and no repair attempts should be performed, as replacement fluid will also darken.
5. Fluid should be between the Min and Max level lines of the label on the fluid reservoir when the Roof is in the closed position/ hydraulic cylinders extended. It is recommended to use a flashlight to view the fluid level.
Adding Hydraulic Fluid to the Folding Top Pump Reservoir
1. Use only approved hydraulic fluid for Hydraulic Folding Top Pump GM P/N 88901975, fluid should be green in color.
Warning: Refer to Eye Protection Warning Eye Protection Warning.
Note: Check and remove any objects inside the rear compartment.
2. Remove the tonneau cover if installed on the vehicle.
3. Park the vehicle on a level surface
4. Remove rear seat back and insulator pad. Refer to Rear Seat Back Cushion Pad Replacement Rear Seat Back Cushion Pad Replacement.
5. Remove the trim cover located in the center top of the rear trim that conceals the access hole for the hydraulic pressure release valve bolt.
6. Manual release valve is operated with a 6mm internal hex wrench. Open valve by turning it counterclockwise, no more than one full turn.
7. Place the folding top in the up /closed position. If Folding Top is inoperable then it can be raised manually at this point.
8. Remove the rear compartment trim to access folding top pump and motor, Reposition the folding top pump and motor without disconnecting the hydraulic lines. Refer to Folding Top Pump with Motor Replacement Service and Repair.
9. Place protective covering on the load floor, wrap the pump and motor in shop towel to control any hydraulic fluid spillage.
10. Remove the 13mm Hex fill plug. With pump level fill/ folding top closed position, fill reservoir (1) until the fluid level is between the min and max lines on the reservoir fluid label.
11. Remove the 13mm Hex fill plug.
12. With pump level fill/ folding top closed position, fill reservoir until the fluid level is between the min and max lines on the reservoir fluid label.
Note: To properly gage the fluid level the cylinder rods need to be extended or roof in closed position. There no way to see the fluid label unless the pump bracket is removed.
13. If the system has been extremely low on fluid it may be necessary to bleed air out of the hoses and cylinders. Do the following:
1. Install and tighten the reservoir fill plug, tighten the plug to 2 Nm (18 lb in).
2. Install the pump and bracket,
3. Ensure that the Manual Bypass Valve is closed.
4. Operating the folding top open and close fully 3 - 4 times or until air noise is no longer heard. It may take a few tries to complete this.
5. Refilling the reservoir and bleed before enough air is purged.
Note: Fluid should be between the Min and Max level lines of the label on the fluid reservoir when the Roof is in the closed position/ hydraulic cylinders extended. It is recommended to use a flashlight to view the fluid level.
6. When finish verify that the fluid level is between the Min and Max lines with the folding top pump and closed.
Caution: Refer to Fastener Caution Fastener Caution.
7. Ensure that the fill plug and wipe pump and motor clean.
Tighten the plug to 2 Nm (18 lb in).
14. Install the rear seat back and insulator pad. Refer to Rear Seat Back Cushion Pad Replacement Rear Seat Back Cushion Pad Replacement.
15. Install all rear compartment trim when the folding top pump was removed. Refer to Folding Top Pump with Motor Replacement Service and Repair.
16. Close the rear compartment.
17. Inspect the folding top for proper operation. Refer to Power Folding Top Description and Operation Power Folding Top.