Top Hydraulics

Hello Ville,

obviously, I cannot give you a perfect diagnosis based on what you are writing, but the likelihood of my previous response being correct should be close to 99%. Everything you are describing is consistent with internal bypasses.

You will not necessarily have external leaks if there is an internal bypass, and internal bypasses will not result in codes from the controller.

One thing leads to another. There are eight cylinders in your '89 that are in imminent danger of having the piston seals falling apart, based on what I'm reading. You not having any external leaks yet is an extremely rare case for an R129 - you must live way up North. Any of your twelve cylinders may be leaking externally very soon; you have been very lucky so far. A further complication is that fragments from disintegrating piston seals can impact the valve blocks under the roll bar, and that's where diagnosis becomes ugly.

My honest, best advice is dealing with all twelve cylinders at the same time. Send them in for rebuild service, and it will cost you only $550 plus shipping. Even with all cylinders attached to the locks, return shipping by International Express Mail (EMS) is only $80. We ship internationally every day.

Klaus

www.tophydraulicsinc.com

FalconChief

I just changed all 12 of my cylinders in my 1996 SL500. They were rebuilt by Top Hydraulics. After putting my system back together and topping off the hydraulic fluid I found a leak in the distributor! I would change the seals in it as well. Once these seals start to fail they will all fail eventually. Unless you enjoy removing & replacing cylinders I'd do them ALL at the same time.

Once everything was replaced I had to cycle the top 6 or 7 times to get the cylinders all in sync & primed with fluid. Top works just great now!

Top Hydraulics

FalconChief,

thanks for sharing! We don't want people to think we are trying to up-sell them when we suggest that they have us rebuild the front distributor p/n A 129 800 00 22 at the same time as the full set of cylinders. That's why we recommend to do the distributor upgrade for ANY R129 SL that is 20 years or older, and also for those younger SLs which are or in a hot climate, or have been there for a while.

Maybe we should be a bit more aggressive with our recommendation regarding the distributor, seeing how many distributors we are getting in from younger cars lately.

Rebuild & upgrade service for the distributor only: http://www.tophydraulicsinc.com/en/r...indshield.html
Rebuild & upgrade service for the full set of cylinders with distributor: http://www.tophydraulicsinc.com/en/r...stributor.html or http://www.tophydraulicsinc.com/en/r...stributor.html
Rebuild & upgrade service for full set of cylinders only: http://www.tophydraulicsinc.com/en/r...-set-r129.html or http://www.tophydraulicsinc.com/en/r...-set-r129.html

Klaus

www.tophydraulicinc.com

VilleVantaa

Hi again!

Today I dissemble all 12-cylinder's. It took 4hrs, and it was quite easy with TH's guide.
Only problem was with right main lift cylinder. Bolt, wich is bottom of cylinder, broke.
So I think there is no way to get it off. Luckily there is enough space, so I can open cylinder and
replace only o-ring. Or do anyone have idea, how I can get that broken bolt off?
Next I will pack those cylinder's and sent to Klaus and wait new ones arrive.

Ville

Top Hydraulics

Ville,

on model years 1990 and 1991 (also model year 1989 in Europe), Mercedes used a poorly designed bolt for the bottom of the main lift cylinder. It requires an 8-mm Allen wrench (inside hex bolt). Poorly fitting wrenches might slip and wear out the inside hex. Even if the wrench is a tight fit, you may end up with a cracked head on the bolt, in case the bolt is threaded in very tightly. This is rare, and there are several ways to deal with it. More detail can be found in the following thread: http://www.benzworld.org/forums/r129...nder-bolt.html

Here is a picture of such a bolt with cracked head:


How to extract the broken bolt:

1) Use a special 14-mm tool that latches on to the outside of the bolt and allows you to extract it. A customer told me that it worked great for him, but I cannot remember the brand or exact name of that tool.
2) Hammer a 13-mm socket onto the outside of the bolt, and extract the bolt that way. Here is a photo of how BenzWorld's "aam" did the job:


The extracted bolt:



How the 13-mm socket fit onto the outside of the bolt:




(If this fails, then you can still saw off the bolt with a very fine blade right next to the cylinder bottom.)

I hope this helps. The replacement bolt from Mercedes is p/n 129 991 02 12.

Klaus

www.tophydraulicsinc.com