How to interpret LHM level indicator
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Thread: How to interpret LHM level indicator

  1. #1
    Tadpole
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    Default Replacing accumulator sphere - couple of questions

    I need to replace a sphere so before I do I checked the level on the LHM reservoir. At full height, it's level with the top red ring.

    Does this indicate it's got plenty, or I need to top up?

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    Last edited by kenbw2; 3rd November 2019 at 01:01 PM.

  2. #2
    Fellow Frogger
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    Yes, it needs to be between the two rings at maximum height. When you have flat spheres, it is possible to overfill it because more fluid is pushed into the flat spheres than was intended. You may find the level seems to mysteriously rise a little after you change spheres assuming you haven't lost much in the change. Fitting spheres is like fitting an oil filter - screw on until it touches the rubber seal and then maybe a 1/4+ hand turn after that. It doesn't have to make contact metal to metal.
    If it has anti-sink suspension, the suspension won't depressurise just by releasing the regulator bleed screw. You need to set it to low with the engine running and after that you can release the pressure regulator bleed screw.

  3. #3
    Tadpole
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    Quote Originally Posted by David S View Post
    Yes, it needs to be between the two rings at maximum height. When you have flat spheres, it is possible to overfill it because more fluid is pushed into the flat spheres than was intended. You may find the level seems to mysteriously rise a little after you change spheres assuming you haven't lost much in the change.
    If I do find it's above the top line after the swap do I need to remove some fluid?

    Quote Originally Posted by David S View Post
    Fitting spheres is like fitting an oil filter - screw on until it touches the rubber seal and then maybe a 1/4+ hand turn after that. It doesn't have to make contact metal to metal.
    Sounds good. Off to get a strap wrench!

    Quote Originally Posted by David S View Post
    If it has anti-sink suspension, the suspension won't depressurise just by releasing the regulator bleed screw. You need to set it to low with the engine running and after that you can release the pressure regulator bleed screw.
    It does, and I did that - dropped it to mimum height until it sank, turned the engine off and then released the screw by a turn.

    I didn't hear the hissing sound I've been told to listen out for. Could that just be the fact that I have no pressure to release? (hence why I'm replacing the accumulator sphere!)
    Last edited by kenbw2; 3rd November 2019 at 01:02 PM.

  4. #4
    Fellow Frogger
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    A half turn on the regulator release screw is usually enough. You should hear a hiss of fluid escaping and returning to the reservoir if the accumulator has at least some pressure. If it doesn't, then the accumulator may be flat and you would probably have the pump trying to charge the accumulator all the time and not cutting out. The brakes will still work with a flat accumulator and a good pump, but you are requiring the pump to do a lot of work and you may experience some slight judder and intermittent flashing of the pressure warning light. If in doubt, it is best to replace the accumulator.

    From and earlier photo you posted, you might also look into Forever Black for faded door moulds, bumpers and mirrors that should be black.
    Caisson likes this.

  5. #5
    Tadpole
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    Quote Originally Posted by David S View Post
    A half turn on the regulator release screw is usually enough. You should hear a hiss of fluid escaping and returning to the reservoir if the accumulator has at least some pressure. If it doesn't, then the accumulator may be flat and you would probably have the pump trying to charge the accumulator all the time and not cutting out. The brakes will still work with a flat accumulator and a good pump, but you are requiring the pump to do a lot of work and you may experience some slight judder and intermittent flashing of the pressure warning light. If in doubt, it is best to replace the accumulator.
    Yea the pump is working very hard, it pains me hearing it click every few seconds. I brought the accumulator sphere with me for that reason, hopefully it'll be better shortly once the new one's on!

    Quote Originally Posted by David S View Post
    From and earlier photo you posted, you might also look into Forever Black for faded door moulds, bumpers and mirrors that should be black.
    Yep! I'm gonna get the mechanical stuff out of the way first (next up is the exhaust back box) then deal with aesthetics.

  6. #6
    Fellow Frogger
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    If you have the 6+2 pump, you may find changing the accumulator stops the leak from the line from the 2 piston side of the pump to the regulator. When the accumulator is flat, that line will experience high transient pressures and it might weep around the fittings. It's not something you want to leave in that condition for long.

  7. #7
    Tadpole
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    I appreciate all the help David!

    So I've taken the sphere off, and found the inside of it is different to the one I intend to replace it with. It was listed on eBay as an accumulator sphere.

    The one on the left is the one I bought, the right is what came off the car:





    Does this matter?
    Last edited by kenbw2; 3rd November 2019 at 02:44 PM.

  8. #8
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    Looks like you have acquired a suspension sphere with different volume to your accumulator and presumably different gas pressure. The pressure is stamped on the sphere usually.
    Does it matter? Some pressure is better than none obviously.
    Never done it, but I have been told by a citroen mechanic that a suspension sphere can replace an accumulator.

    Sent from my LG-K520 using aussiefrogs mobile app

  9. #9
    Fellow Frogger
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    That's a non-Hydractive front sphere, not an accumulator. You shouldn't use it in place of the accumulator unless you grind back the edge peening that retains the damper and can remove it. Once that is done, it will have the same form as the failed accumulator. It's nominally filled to 70 Bar (seems too high. Most likely 50 or 55) if I am reading the box label correctly. A 400cc accumulator is nominally filled to 62 Bar, but it is allowed to be 62Bar +5/-32Bar, so you should get away with it here. However, the production date on the label appears to be 9812, so you are dealing with a 20yo sphere and there is no guarantee it will 1) still have the nominal pressure and 2) last all that long. The label suggests it has a 'Desmopan' diaphragm, but check if it has three dimples around the filling plug that would indicate it has a multi-membrane diaphragm. The factory part for this application with the multiple membrane would be painted grey these days.

  10. #10
    Tadpole
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    No dimples around the top unfortunately. You might be right about the pressure, but if it's the wrong part then it's useless to me anyway. Looks like I'll be doing a refund claim

    I did also bring an anti sink sphere with me. Could I use this in place of the accumulator?

    I guess the question is which is my best option until I can get my old accumulator replaced/regassed?

    - Put the old flat accumulator back on (I've confirmed there's no gas - I carefully put a screwdriver in and it travels to the end of the sphere)
    - Put the anti sink sphere on the accumulator (if this can be done)





  11. #11
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    I would think the anti-sink sphere would be OK for the moment as it doesn't have a damper inside it and should still screw on and seal. The pressure won't be quite right and not 62Bar (book says anti-sink sphere should be 400cc 50Bar +5/-20), but it will be close enough to do the job for now.
    You won't be able to regas the original accumulator if you can push the diaphragm in because it has obviously ruptured. It is most likely full of old LHM. Buy a new one.

  12. #12
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    Quote Originally Posted by David S View Post
    You won't be able to regas the original accumulator if you can push the diaphragm in because it has obviously ruptured. It is most likely full of old LHM. Buy a new one.
    I tried! For what it's worth, I'm not really pushing it in - it's just already all the way at the bottom.

    Quote Originally Posted by David S View Post
    I would think the anti-sink sphere would be OK for the moment as it doesn't have a damper inside it and should still screw on and seal. The pressure won't be quite right and not 62Bar (book says anti-sink sphere should be 400cc 50Bar +5/-20), but it will be close enough to do the job for now.
    Alright, I'll see how I get on with sourcing an accumulator sphere. If it looks like it's gonna be a while I'll put the anti sink one on and make do with that.

    Thanks for your help!

  13. #13
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    Only one comment from me: I'd suggest getting new IFHS spheres from them or a dealer (probably NA in Oz) - do some googling. You should have them within a week or so.
    JohnW

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