2002+ Cylinder Replacement & Bleeding for top

[ccimino]

Here are the steps I took to replace the convertible top cylinders after one finally began leaking (2002 with 67k). Same steps if just topping up with fluid and bleeding (usually the issue when the top starts taking longer to lift or squeals in the process). Note that I removed the trim and backplate in the parcel shelf area behind the seats to create more room as the work is done with the top up. Anyone who’s ever cleaned the rear window inside knows there is barely 11 inches clearance between the top of the back plate and the roof. With the backplate removed, this becomes 25 inches. If you don’t need the space (or have a talented 8 yr old who can fit in the well and follows instructions), you can skip steps 1-4. Otherwise, with the top down, and the seats all the way forward:

1. Unbolt the lower seat belt anchors (T-47 torx bit)
2. Remove the small plastic covers to the upper seat belt anchors
3. Remove the 5 trim panels from the back parcel shelf area. All five are held in with flat metal friction pins. Plastic trim tools work well to pry the pins out. I do not recommend a screwdriver or anything that can scratch the plastic. Remove the two curved corner panels first.
4. Raise the top
5. Unsnap the cloth cover on each side where it hides the carriage linkage and cylinders. Fold these back and clamp to the top liner with a small clamp or binder clip
6. Remove the 7/16” bolt that connects the rear window defroster body ground on the back metal bulkhead under the window on the driver side (don’t drop it!)
7. Unplug the defroster wire connector attached to the same metal bulkhead on the passenger side
8. Pull both wires through the cloth cover and tuck into the same fold clipped to the liner from step 5.
9. Starting at one end, unhook the cloth cover from the rear deck trim. These are held in place with plastic tabs in the seam of the cover. There is an open oval in the tab that slips on/off a plastic/rubber head. Pull gently, or pry with a plastic trim tool.
10. On each side where the cloth cover meets the carriage hinges, pry the cover back with the trim tool to remove the 3-4 plastic push pins.
11. Unbolt the metal backplate – Eight 1/2” bolts total: 2 on each side of the uprights and 4 bolts on the lower deck (peel back the curved carpet). You may need to slacken the seat belt retractors to access the bottom bolts on the sides. Also remove the lower retractor torx bolts (T-47)
12. Unplug the speakers and remove the backplate with the cloth cover attached. Now you can more easily access the top motor/reservoir, hydraulic lines and lift cylinders.
13. If you are just checking fluid/bleeding the system, you can leave the motor in place and pry out the rubber plug near the top of the side panel on the driver side of the motor/reservoir. The unit is wrapped in an insulating cover for noise. You may need to pull back the flap to access the fill plug. The plug is an inch long. I used needle nose plyers and went slow so as not to tear it. Once out, use a small squeeze bottle or turkey baster to top up with multipurpose Mercon ATF to the bottom edge of the opening. Place a shop wrap or paper towel to catch fluid that seeps out. Run the top through a full cycle to lower and lift. Leave the rubber plug out while bleeding. Check the fluid level after each full cycle. When no more fluid is needed, and the down/up cycle is smooth, reinsert the rubber plug. If not replacing cylinders or lines, skip the rest. Reassembly is the reverse of above.
14. Since I was replacing the lift cylinders or lines, I found it easiest to remove the entire system and work on it out of the car.
15. The motor/reservoir is attached to mounting plate with 4 rubber plugs that can be pried apart. Do not use a screwdriver or anything sharp that could tear the rubber. Clean and inspect when out. I soaked mine in silicone spray.
16. Unplug the wire connector.
17. Unhook the hydraulic lines from the plastic mounting straps on the tubular frame.
18. The cylinders are mounted in two places: a T-40 torx bolt where the shaft loop end connects to the carriage, and a 1/2” nut to metal bracket that holds the top of the cylinder body. The bracket is 3-4 inches long with a tab on one end that inserts to the carriage.
19. Remove entire system and disassemble out of the car, noting which line goes where. Remove the insulation cover. The cylinder hose fittings are 7/16”. The fittings at the motor/reservoir are 1/2”. While only one cylinder was leaking, I replaced both cylinders and all 4 lines with new parts for $350 from Hydro-E-Lectric. It seemed like cheap insurance for the labor and time invested.
20. I used Teflon tape for each brass to aluminum fitting. These get snugged tight, not torqued!
21. Once assembled, I added new multipurpose Mercon ATF to the fill hole. Using an old motorcycle battery I keep around as a 12 volt power supply connected to the wire pigtail, I ran the system through its cycle, reversing the polarity to change cylinder rod direction in or out. Bleed as described in step 13. Don’t worry if you don’t get every last air bubble out of a line. As long as you are not still adding fluid after 3-4 full cycles, the system is bled. I reattached the insulation cover with long zip strips.
22. Install the entire system running the cylinders under the tubular frame sections (an extra pair of hands can be helpful here). Be careful not to kink hoses or have any areas where the hose may rub against a sharp edge. Loosen the fittings just enough to turn the hoses if needed, then retighten.
23. Once both cylinders are in place (and the motor/reservoir wire is reconnected) use the dash switch to extend/retract the rods to align the holes. I used blue thread locker on everything.
24. Reassembly is the reverse of above. Be sure to reconnect defroster and speakers.

All told, the process took 5 hours. No surprises, except for the dropped 7/16” bolt for the RWD ground wire. Thank goodness for the flexible magnetic wand. Sorry I didn’t take pics along the way. Hopefully the steps above are descriptive enough to muddle through. Go slow, take your time. You can do this.

 

[biddle]

Also suggested that everyone have a service manual on hand as a good reference.

 

[Rick4852]

Does anyone know the secret to replacing the rubber plug on convertible top fluid pump