360 spider oil leak appearing on soft top when folded up inside car

Discussion in '360/430' started by dhallag, Jul 9, 2016.

  1. dhallag

    dhallag Rookie

    Dec 3, 2010
    Chicago, IL
    Full Name:
    Darien Hallagan
    hello. i have a 2004 360 modena spider. it's got 1800 miles and i only drive it every two weeks about 20 miles or so... when i drive the car, i always take the top down. just the other day, i noticed that there is an oil leak that appears only on the right side of the window portion of the top and a bit on the black canvas on the lower right of the window. as it's smeared on, i estimate it's about 1/2 ounce. i only see it when i park the car and put the top back up after use. the oil is completely clear. gauges when i use the car are normal. when putting the top up/down, i can stop the process about half way and looking around, i can't see anything around that has oil on it -- so the oil is only manifesting itself on the top. after use, i clean it and the next time i use the car, i only see the oil again after use. this has happened twice. i am going to use it again tomorrow and anticipate the same thing happening and was hoping you might have some troubleshooting ideas...

    has anyone else had this problem and any ideas what this might be?

    thanks much... darien
  2. solly

    solly Formula 3

    Jun 2, 2001
    Westchester NY
    Full Name:
    Dr. Steven S.
    Unfortunately a very common problem on 360 spiders. Many articles on it. I have a similar problem. For some odd reason the tops are actually made by Mercedes and have about a thousand sensors and hundreds of moving parts, all built by the lowest bidder.

    Here is what happens: After a while the pistons (I believe there are 2 main pistons besides all the small motors that operate all the panels) start to leak. Mine started in 2002, only 6 months after I bought the car new from Shelton. So some of the hydraulic fluid bypasses the piston seal and leaks out. From what I know, most leaks are internal so you never actually see the fluid. When the piston moves back the fluid just flows around the leak area the other way. Although some must be lost to the outside, or we would never have to refill the reservoirs. I've just never seen it.

    It doesn't seem to matter how much you drive it or how many miles are on it. The seals degrade over time, whether it's driven or not. Some (like mine) were faulty from day one.

    I don't know why your fluid is clear, as the replacement fluid from Mercedes is green. Perhaps the fluid was clear from the factory, and the formula changed at some time. In any event, the main symptom is a convertible top that is reluctant to open or close all the way. I was once stranded with a top half closed. You don't ever want to use the mechanical alternative to opening or closing one. It takes 2 people, one of whom needs to be an astrophysicist. Lucky I was in Greenwich shopping with my daughter, only 2 minutes from Miller Ferrari.

    Replacement of the entire top mechanism is around $40,000 with labor. Replacement of just the pistons is about $7,000 with labor. Most of us just refill the reservoir every so often which is quite simple and costs about $27 for a bottle of Mercedes hydraulic fluid and a half hour of simple work.

    I don't know why your leak is showing up on the fabric. Then again I am not familiar with every hydraulic connection back there. Certainly hydraulic fluid can damage the fabric top and the plastic window if exposed often. But I can't think of any other fluid that would be in that area. Nor can I think of any clear fluid anywhere in the car. Are you certain the fluid is clear? What type of consistency does it have (thin, thick, oily)? Does it have a recognizable odor?

    If the top opens and closes normally as you have stated, and doesn't sound like it's struggling then you are either OK as far as the mechanism goes and the clear fluid is an anomaly, or you are at an early point in the failure cycle. Unfortunately there is no preventive maintenance or easy fix. Either way get it checked out ASAP.
  3. vrsurgeon

    vrsurgeon F1 World Champ
    Silver Subscribed

    Dec 13, 2009
    Charleston, SC
    Full Name:
  4. dhallag

    dhallag Rookie

    Dec 3, 2010
    Chicago, IL
    Full Name:
    Darien Hallagan
    thank you so much for the detailed explanation. so you're saying it's the hydraulic fluid in the pistons for the mechanism that opens and closes the top. To answer your questions about the fluid:
    - it does have a very slight yellow color to it. when taking it off with a microfiber cloth, it barley shows any color
    - the consistency is oily, thin and smells like light motor oil

    i'll take a picture of it and post after my drive today.

    so each piston has it's own reservoir -- is there a schematic that shows the location of the pistons and how to open the reservoir to add fluid?
  5. shad99

    shad99 Formula Junior
    Silver Subscribed

    Dec 12, 2013
    Japatul Valley, CA
    Full Name:
    This company will replace seals in any of the rams for $150. They also sell hydraulic line couplers which saves the royal PITA of re-routing the lines. I haven't used them yet but intend to as I have a cover ram which has blown seals.
  6. John_K_348

    John_K_348 F1 Rookie

    Sep 20, 2013
    Boston, MA
    Full Name:
    John E. Kenney
    Wow great info. Duly noted.

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