R129 SL500 hydraulics problem
 

New to me 2000 SL500 hydraulics leaking. Got the soft top back up but need to replace rear hydraulics. I'm not sure exactly which one is leaking but I'm getting hydraulic fluid in front of the rear passenger side tire. I'm going to refill the hydraulic fluid on Saturday. I'd like to put the hard top on for now and deal with all 11 cylinders as an early winter project. Or should I just take care of the one leaking cylinder now and deal with the rest over the winter?

Thoughts on next steps?

there are three cylinders that could be leaking. the bow cylinder is the most likely and it can leak down on the larger top cylinder making you think that is the one. you will want to send it in to be rebuilt. you may want to do all while you're in there. it helps to have a second pair of hands when re-installing the bow cylinder, it's easy to bend the micro-switch/sensor holder, drivers side only. that is the hardest one to install of all of them. all the rest are fairly easy. the top storage cover latch is accessed in the storage compartment and is easy to get at. make sure you pay attention to the nut markings on the cover latch assembly and bow lock assembly when re-installing. check the front latch cylinders above the visors. call klaus witte at 541 902 3214. he's done 7 for me and no issues. Around $55 each. he will at no extra charge take the cylinder out of the assemblies for you. be very careful of the pistons. you'll have to remove the interior parts behind the front seats to access bow and top cylinder, along with accessing through the top storage compartment. there are two cylinders on each side in the trunk. leave hard top off if you plan on working on it.

I added hydraulic fluid and I was able to get the system primed and working. I now have the top stowed in the open position. Then, I was nearly locked out of the trunk. Does the trunk release also work off of the hydraulic system?

the locks are on a pneumatic/air system. that pump is located in the trunk by the right hinge

Thanks. I finally got into the trunk. I think I'll put the hard top on for now and deal with the leaky hydraulics when I get some down time.

again I would recommend rebuilding all cylinders at first signs of leaks to save going back into the system again and again. after replacing the cylinders on the drivers side a year ago and inspecting the passenger side cylinders, they showed no sign of leaks. a year later three of five were leaking. I should say two were slightly leaking, the bow cylinder was gushing. they will all fail in time and 27 years is about time for rebuilding. the final bunch of old ones are being rebuilt now, should be in soon.

things didn't go as the drivers side did. this job requires patience. these cylinder bolts have access holes inside under the rear interior trim. you'll have to move the top into different positions to access bow cylinder bolt and you'll need a 5 or 6 (?) hex/allen for the bow and a 8mm hex/allen for the top cylinder . when I tried to put the bow cylinder bolt in on the new cylinder it wouldn't go in. the shaft was slightly bent, it took me awhile to figure that one out. I ground down the tip of the shaft to make it more pointy so the treads would catch and then it would force the shaft straight as it was screwed into place. the top cylinder bolt was another problem because a large amount of wiring coming across the access hole, mostly going to the top controller, no wiring in the way on drivers side. when re-installing, I had it close, when I looked to see if it was going into place right, the wiring pulled the bolt back enough for the bolt to drop into the rocker. real fun. I had to finally go into the wheel well, pull the wheel well liner (it was pretty filthy) and grind a slot big enough to fish the bolt out with a magnet. there are holes in the wheel well with plugs. I removed the most inside plug and ground two strips on each side of the hole, then pulled the metal down and got the bolt, then bent the metal back in place. one if careful could grind the bolt access hole too, be careful not to hit something else, it's tight for a grinder. the metal in the unitized body is substantial. in other words, don't drop the bolt. when installing cylinders make sure the retaining clips are in the cylinder first, except on the bow cylinder, there you need to hook up hydraulic lines to the cylinder before putting in place. took me almost 15 hours to finish the job. without problems it should take about 6 to 8 hrs. make sure the lock cylinder assemblies are plugged in.