When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
2011 E350 Convertible Soft Top - Leaking Hydraulic Fluid Lines
Hello All,
Can someone help me with this problem? I believe it to be a bad design / premature failure and should be a recall item paid for my Mercedes Benz.
My 2011 E350 soft convertible top is leaking hydraulic fluid from the flexible tubing running through the soft top roof (drivers side) to the locking mechanism which secures it to the windshield. The hydraulic fluid leak developed where the top folds in half when raised or lowered. I live in the northeast where summers are short and hence raise and lower the roof for less than half the year.
Same exact line failure, line split at hinge point on drivers side where two lines run to the front locking latch. Definitely a poor design as the lines do not have a flex joint at the hinge point to allow for repeated bending during operation of the top. Line cracked and pumped fluid all over the rear seat and soaked the headliner. Waiting for resolution by MB dealer.
Found a solution for repairing the cracked hydraulic line at the front hinge point. MB will not repair anything and quoted replacing the front latch ram with a new line back to the hydraulic pump in the trunk. Requires removing and reinstalling many components of the top, (read as big labor bill). I found a company in Florida who sells convertible top hydraulic line repair products on eBay (cabriolet hydraulics). They have a hydraulic line splice kit with two connectors (unions) that work well. Included is a length of replacement hydraulic line. The kit seems a bit pricey, but works perfectly. I called them with a question about my repair and they passed me to a tech who was quite helpful. This repair took less than an hour without removing any top components as the line was split right above the driver door rail front hinge point. Total cost of repair kit and a liter of MB hydraulic fluid $116. Saved $$$$. I found that the two lines above the driver door leading to the front latch rams are supposed to rest in side a series of plastic clips attached to the top side rails. The lines can slip out of the clips, especially at the hinge point. I added a loose zip tie on those clips to keep the lines away from the hinge. A better clip design, with a flexible line at the hinge point would eliminate spraying hydraulic fluid all over the interior of the car when the line fails.
I have the same problem at a different location, there seem to be a problem with the routing of the lines to the soft top actuation hydraulic cylinder as these are folded double when the roof closes. In one of these folds it now developed a leak.
Are these lines available from the dealerships? I will have to replace the leaking one plus two others which are obviously near braking point.
I’d suggest the same fix as I detailed above, contact Cabriolet Hydraulics and purchase several splice kits and repair the cracked lines. Be sure to check the hydraulic reservoir in the trunk and refill with the correct fluid (be careful as it is not power steering fluid as my dealer tried to sell me). These splice repairs are permanent and much less costly than buying new lines and associated parts, not to mention the labor savings. Talk to the tech, they will sell you the amount of hydraulic line you need to do the repairs. These lines operate under high pressure (up to 600 psi) and will discharge quickly. For my repair the tech stated there wee two sizes of hydraulic lines (diameter) almost the same size, and the splice connector works for both sizes. Mine used the larger of the two sized lines. For an idea of the savings versus the dealer repair, I was quoted 4 x $$$$ to replace one line, including disassembly of the convertible top and installation. Good luck.
which has got me very worried as the Car Wizard says that this is a very expensive repair. Then I found this thread which is giving me hope.
Is the repair using the Cabriolet Hydraulic Couplers still working? Do I need to cut out a section and add a new piece of hose between two couplers to allow more room for the cable to flex? Or can I just put one coupler in where the hairline crack is? Or should I buy a complete new hose from Merc and patch it in towards the back of the soft top? Can I do the repair myself or should I get a mechanic to do it? I spoke to several local hydraulic repair people in the UK who said that they only replace hoses and don't splice them. None of them seemed keen on using a repair kit that I bought from the US. But perhaps I could find one to do the repair if it is difficult.
which has got me very worried as the Car Wizard says that this is a very expensive repair. Then I found this thread which is giving me hope.
Is the repair using the Cabriolet Hydraulic Couplers still working? Do I need to cut out a section and add a new piece of hose between two couplers to allow more room for the cable to flex? Or can I just put one coupler in where the hairline crack is? Or should I buy a complete new hose from Merc and patch it in towards the back of the soft top? Can I do the repair myself or should I get a mechanic to do it? I spoke to several local hydraulic repair people in the UK who said that they only replace hoses and don't splice them. None of them seemed keen on using a repair kit that I bought from the US. But perhaps I could find one to do the repair if it is difficult.
Your comments gratefully appreciated
The repair using hydraulic line splicers is permanent. Since installing the line splice I have had no issues at all. These connectors (unions) are touted as using the same design technology used in repairing aircraft hydraulic lines (good enough for my Benz). They are basically compression fittings. The guy in the repair wizard video needs to get up to speed on repairing the line at the failure point, not dissembling the entire car (just as the MB dealer wanted to do) and replace the entire line. Absolutely not necessary. The failure at the hinge point is because the hose (either one of two hoses on the drivers side) slips out of the plastic holders and gets caught near the hinge and crimps it which causes a split or crack in the line which leaks. Keeping both of the hoses away from the hinge point is the answer. The repair I outlined is simple, inexpensive and permanent. You are basically installing a short piece of new line in between two compression unions to remove the failed part of the line. Then reinsert the lines into the plastic clips to support the lines away from the hinge point in the top rail. I added several zip ties along the rail to hold both lines securely and insure proper alignment away from the hinge, being careful not to tighten closely at the hinge point and therefore allowing them to flex properly, which they will. Refill the hydraulic fluid reservoir tank located on the left forward side inside the trunk (with the correct fluid - not power steering fluid) and you are done. I did not need to increase the length of the line when I added the splice. I measured the length of the line with the two unions and replaced it to be the same length, about 8 inches in total. In my case the line was not too short, it simply slipped out of place and into the hinge point. My only concern was the need to somehow bleed the hydraulic line after the repair to remove any air introduced by the new short piece of spliced line - not needed. This is a high pressure line and it works perfectly after the repair. The line is not under pressure when not operating, it is only pressurized to actuate the front rams to lock or unlock. So you can partially open the top for access to repair it and the lines don’t drain out. This repair is a no brainer. Just remember that the spice connectors are one time use - you cannot tighten them and remove them to use over again so it’s wise to manually check fitment before tightening them in place. These are similar to plumbing compression fittings, you insert the line at each end firmly into the fitting until it stops, then tighten securely until the compression nut seats against the center union. Actually a simple repair that should take an hour or less, even moving slowly to double check everything. This is another case of seeing the forest through the trees, a repair instead of a $4,000 replacement bill. Good luck.
Hi CWCarUso
Many thanks for your full and helpful reply.
I've contacted Jason at Cabriolet Hydraulics and they're going to ship over their kit. It works out expensive with the shipping and import tax at $150 for two couplers and 12 inches of hose but if it solves the problem then it'll be an absolute bargain.
I might ask the mechanic to do it when it goes in for some other work. For instance, I was looking at the hydraulic tank and guess that I would have to buy a pipette to fill it up as the cap is in a such an awkward position. But if he doesn't want to do it - or it arrives too late I will attempt it myself.
Hi CWCarUso
Many thanks for your full and helpful reply.
I've contacted Jason at Cabriolet Hydraulics and they're going to ship over their kit. It works out expensive with the shipping and import tax at $150 for two couplers and 12 inches of hose but if it solves the problem then it'll be an absolute bargain.
I might ask the mechanic to do it when it goes in for some other work. For instance, I was looking at the hydraulic tank and guess that I would have to buy a pipette to fill it up as the cap is in a such an awkward position. But if he doesn't want to do it - or it arrives too late I will attempt it myself.
Many thanks indeed
All done.
Got the kit- fortunately HMRC didn't add the VAT - so with postage it was $132 - ridiculous for what it was but bargain of the century if it holds. Took 4 days to arrive from the USA to the UK, and was advertised as kit especially for E Class A207 cabriolets!!
Cwcaruso's instructions (above) were great and especially his photo. Suggest that you look at this first.
All I will add to anybody doing this repair is that:
1. I initially couldn't get the top open. Lifting the lever unclipped the latches (squirting lots of fluid). Initially I couldn't manually open the top as it wouldn't fold back. But after I lifted the back tonneau / hood cover between boot and back seats up to fully vertical - it was easy to fold. Lifting the hood to half open gives good access - almost certainly necessary.
2. The clips securing the hoses seemed undamaged - but it looked like they had somehow opened. This had caused hose to crack on the hood fold and so leak badly. The other hose has a slight kink but looks like it is still okay. After finishing the job, I closed the clips up, added a couple of cable ties for good measure and have ordered some self amalgamating hose repair tapeoff eBay for £5 to wrap around to give a bit more protection if it will stick.
3. the fit between the couplers and the 12" of hose provided in the Cabriolet Hydraulics kit was tight. I suggest that you put the couplers on this first as you can do this on the workbench / kitchen table.
4. the couplers slipped very easy on the hoses already installed. Despite lots of claims that you wouldn't be able to slip these on and off - this wasn't the case. I tried to get the couplers positioned so that they were securely in the place where the hose doesn't bend and enough space that the hose can still slip through the clips.
5. The hood wouldn't close again when pushing the lever due to all the lost hydraulic fluid But it would fully open so allowing me access to the hydraulic reservoir is in the little hatch on the lhs of the boot. There is a little 13mm nut on the top allowing access (I would be careful not to drop it : ) )
6. It was practically empty - well below Min. I used my pipette for testing up antifreeze to fill it up (until it broke and had to buy a syringe). It is self bleeding and took 300ml to fill up. I used the Febi ZH-M. I am attaching the spec sheet.
7. Guess that I will need to check level after opening and closing it a few times. And to check the clips / cable routing.
8. Hydraulic fluid looks like it made my black seats come a treat - better than Simonz Leather Conditioner!!
I fixed the exact same line in my 2011 E350 2 years ago and it just started leaking again! Bad design right at the joint above the left side of the driver seat. Now to decide if I replace the lines again or try to splice the line. arghh
06-06-2017, 08:45 AM
