I hav a 92 500 SL with leaking hydro cylinders for the boot and latches. After getting them rebuilt, I cannot get the computer and pump to operate the system. Is there a way to bleed the system or other trick to get the system to work after replacing those cylinders? Thanks for any help.

Check that fuses #3 and #7 in the the trunk fuse box are okay. These supply power to the top controller and the hydraulic pump. If they are okay, remove the control relay for the hydraulic pump (picture) and check for battery voltage across sockets #4 and #5 or the relay's connector. If you perform these checks and write back I can suggest a next step.

Thank you for answering my plea. The pump is getting power, and will operate the roll bar. But the power signal to the solenoid on the pump that routes fluid to the other solenoid banks (for the various top cyl.) is absent. So I hooked up a separate 12v supply to that solenoid. But I still can't make the top cyl. work and cycle. I was thinking that maybe the system was air bound; does this need to be bled, and if so, how? The manual doesn't mention any particular steps, just remove the old cyl. and install the new. I was going to separately inject fluid into the cyl., put the tubes back in, and manually operate the components so that maybe the fluid frim the cyl. will get back in the lines sufficiently to allow it to work. Am I on the right track? Or is ther a better way? The thing worked fine before I removed the cyl. (except that the cyl. were leaking), so I wouldn't think that the computer is bad. Are rebuilt ones available? Thanks in advance for any help.

I believe it is not necessary to bleed the system, Wayne. And rebuilt controllers are available, though I don't know of any sources. You must be sure to get one for cars made befor January of '94, as that was the point where major redesign occurred.

I suggest your next step should be to check for malfunction codes as explained here. Some codes can inhibit operation of the top. By the way, with your current situation while trying to operate the top you should try pushing on the switch continuously until the lamp inside it begins to flash or until 80 seconds have elapsed to allow a possible new code to register.

Thanks for the quick reply. I will work on these suggestions probably over the next week. First I have to replace the battery, as it has gone dead. Thanks again.