[SOLVED] W126 Radiator top hose leak

Discussion in 'Engine' started by jkeith, Mar 20, 2011.

  1. jkeith

    jkeith Active Member

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    My BEHR radiator has an anoying weep from the top connector.

    Having just replaced the head gasket and then the water pump to cure water and oil leaks, I wonder if it is all linked to a change in coolant antifreeze.

    The connection appears to have a joint in the horizontal plane and I am wary of trying to open this joint as the only retaining feature seems to be the plastic 'clips'. Too much force would snap these and ruin the radiator.

    Has anyone managed to cure a similar leak without replacing the radiator?

    Is it possible to super glue or plastic weld it with an adhesive?

    Any tips would be appreciated.
     
  2. grober

    grober MB Club Veteran

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    A picture would help?
     
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    jkeith

    jkeith Active Member

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    Hi Graham, the connection is the small pipe that comes out of the top of the near side of the radiator and is connected by a rubber pipe across the top of the radiator to the fill tank on the off side. The leak is where the plastic outlet is connected to a 90 degree plastic elbow.

    I'll take a picture and load it tomorrow.
     
  4. kth286

    kth286 Hardcore MB Enthusiast

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    those plastic elbows are (or at least used) to be available from dealer very cheap.
     
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    jkeith

    jkeith Active Member

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    Thanks, however, the availability of the part is not the issue, I am trying to find out if the elbow can be removed without risk of snapping the fixing clips and if a new seal is an effective repair.

    Hoping to get advice from someone who has solved this problem previously.
     
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    jkeith

    jkeith Active Member

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    BEHR top connection 001.jpg

    This is the connection that is leaking
     
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  7. jonnyboy

    jonnyboy Hardcore MB Enthusiast

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    As long as you are careful it's dead easy - 5 min repair.
    Just make sure you have the new part to hand - do NOT be tempted to have a "play" beforehand unless you like walking... ;)
     
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    jkeith

    jkeith Active Member

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    Sorry to be a pain Jonny, how do I avoid damaging the retaining clips?
    Is it better to warm the engine first?
    How does the elbow come out best?
    Does the coolant level need to be reduced or not?

    Just trying to avaoid a diy ''*ock up!
     
  9. jonnyboy

    jonnyboy Hardcore MB Enthusiast

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    To be honest I can't remember as it's been ages since I did one, but I do remember giving her a run then letting it stand a bit to take the heat out of the coolant.
     
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  10. kth286

    kth286 Hardcore MB Enthusiast

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    I never got round to fitting my spare in the end BUT I read instructions as follows if memory serves:

    1. take big hose off and catch fluid.

    2. insert long nose pliers to squeeze the plastic prongs of elbow and pull elbow out.

    3. insert new elbow by pushing into top hole, and will seat itself automatically.
     
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    jkeith

    jkeith Active Member

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    Got the replacement part, disconnected the large radiator top hose (used a large plastic bag without holes to catch the cooolant) and eased the old elbow out with a pair of pliers and a blunt flat bladed screwdriver. I first soaked a rag in boiling water and warmed the old elbow to make it more pliable. It was still tricky to get it out but the two pronged retaining clips were not the main issue, it was the three legs of the male fitting that needed a healthy amount of force to get it out.

    The old seal was eroded to the extent that it was the same diameter as the elbow. The new fitting was simple to fit and the problem has thankfully disappeared.
     
  12. jonnyboy

    jonnyboy Hardcore MB Enthusiast

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    Good job.
     
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