Bora hydraulics question | Page 2 | FerrariChat

Bora hydraulics question

Discussion in 'Maserati' started by mullin, Apr 18, 2015.

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  1. staatsof

    staatsof Nine Time F1 World Champ
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    Mar 13, 2005
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    Bob
    Looks like you need to meticulously go through everything then. Are you wanting to do this yourself or have a shop service it?
    Thorough and careful bleeding is pretty easy to do.
    I'd carefully clean the undercoating off of the fixtures. There are tools for measuring the pressures at various parts of the system.
     
  2. Froggie

    Froggie Formula Junior

    Sep 27, 2017
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    Serge
    I am not equipped to do that myself.
    I will ask my italian cars specialist who is used to service similar LHM vehicles (Bora's, Khamsin's) to do it.
    Hopefully it is only a matter of careful bleeding.
    I will report here therefater.
     
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  3. boralogist

    boralogist Formula Junior

    Jun 21, 2005
    998
    Unfortunately the braking pull you describe has nothing to do with bleeding.
    You will need 2 LHM caliper rebuild seal kits.
    Not the end of the world!
    Take care.
     
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  4. staatsof

    staatsof Nine Time F1 World Champ
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    Do you charge extra for psychic automotive diagnosis. ;)
     
  5. boralogist

    boralogist Formula Junior

    Jun 21, 2005
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    :rolleyes:
     
  6. 71Satisfaction

    71Satisfaction Formula 3

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    #31 71Satisfaction, Jun 15, 2020
    Last edited: Jun 15, 2020
    I'm perhaps late to this thread, but I agree with Bob...

    No matter the condition of the LHM system in my Bora, I have never experienced any sideways pulling of the brakes at all. Period.

    Therefore my suggestion is there is something wrong with one of the calipers, rotors or pads. Because even with air in the system, the individual circuit pressure will distribute itself evenly to each side. NOTE: Look at your Table 9 - the design of the brake lines from the main pressure feeds to the wheels - look at the T fitting marked number 19. That T is as simple as it gets and all pressure is inherently equalized side to side. If it pulls sideways, there must be more of a problem than just air in the system.

    But if you have blinks of the warning lights, it also means you have air in the system*. So do a thorough bleed of the LHM first - it's easy. Start with passenger rear, then driver's rear, then passenger front and driver's front last. Let the LHM out slowly. If you open the bleed vale too much the LHM will just foam up. Bleed with the engine running for constant pressure, and refill the LHM reservoir so you don't pull more air into the system if it gets low. Start there.

    After bleeding, if the brakes don't behave properly, caliper rebuild kits are not costly, and the job is not complicated.

    Yes, you can reuse clean LHM, I filter clean LHM through some material too.

    Cheers,
    - Art

    *The warning lights blink for a short time, because the low pressure condition is quickly overcome by the high PSI of the LHM system. But the air takes a moment of time to compress. You can also feel the moment low pressure as a moment of poor braking action.
     
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  7. Froggie

    Froggie Formula Junior

    Sep 27, 2017
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    Thank you, Bob, boralogist and Art,

    I believe all of you are right in a way.
    Today I drove the car to better evaluate and understand what is at stake.

    The blinking is hectic, but too much frequent not to have an issue that probably is air somewhere.
    Also, sometimes I can indeed feel a time lag between the moment when I press the brake pedal and the moment when the car pulls on the right (always the right), so maybe confirming the presence of air.

    However, when turning the steering wheel at low speeds, I also hear a noise as if something (a piston?) was rubbing againts a disk.
    I also noticed sometimes, when accelerating the car at low speed, a strange grabbing and a rumbling noise as if a disk was braking a wheel.
    And when braking firmly at high speeds, sometimes there is a violent and frighhtening pulling on the right!

    So It may be both an air issue and a caliper(s) issue, with maybe pistons not sliding correctly in some of the calipers.

    I am waiting for the car to be repaired by the shop.
    Certainly a careful and exhaustive bleeding first is required (thx for the tip of slow bleeding to avoid foam forming that would again introduce air in the circuit).

    Then, if problem not solved (probably the case), a calipers check for each wheel and eventual reconditioning may be required.

    I have a question though regarding also the main accumulator.
    It looks to be the original one, so maybe 46 years old.
    If I am not wrong, at that time, the Citroen spheres and accumulators did not use the improved multimembrane technology between nitrogen and LHM. So that the nitrogen pressure decreased regularly upon time, maybe up to 10% per year.
    The initial nitrogen pressure at rest in an accumulator is around 62 bars, and it is required for the system to work that pressure does not decrease below about 15 bars, not to lose the dampening role of the accumulator for the LHM circuit when working bestwwen 140 and 170 bars.
    Do you think that the accumulator should also be replaced?
     
  8. boralogist

    boralogist Formula Junior

    Jun 21, 2005
    998
    Those last a max. of 8-10 years!
    Change IMMEDIATELY!

    Regards.
     
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  9. thecarnut

    thecarnut F1 Rookie
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    +1 The main accumulator screws into the pressure regulator and you just buy a new one, unscrew the old and install the new. The two brake accumulators need to be rebuilt about every 10 years. If you do not know when they were last done then do them now and write the date of the rebuild on the accumulator. I would do these things before anything else as it could be contributing to your other problems.

    Ivan
     
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  10. Froggie

    Froggie Formula Junior

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    The two brake spheres were rebuilt by the seller just before I bought the car, 2.5 years ago.
    My mistake was not to have the main accumulator replaced also during the restoration process, certainly worsening the braking situation now with probably more heavy duty on the pump and the circuit...
    So a new accumulator is also on the to do list!
     
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  11. Froggie

    Froggie Formula Junior

    Sep 27, 2017
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    While waiting to have the car serviced by the shop, I did some more inspection of the hydraulic system to investigate and understand if more components were to be replaced or reconditioned.
    The considerations here under also apply to any of the LHM using Masers of the period.

    On my car, it seems that apart from two braking spheres that were recently reconditioned, all of the components of the LHM braking system look to be original.
    I have understood thar replacing the accumulator of the conjoncteur/disjoncteur (CJDJ) is an obvious requirement for the CJDJ to work properly, as the current accumulator is a sphere using the former Citroën membrane technology of the period (so, nitrogen leak-prone), and not the current and improved one of the "multimembrane" that would have benn very resilient to nitrogen loss.

    For other components now.
    From reading in Citroen fora, I understand that the bodies of the "passive" essential components that are the CJ/DJ (piece Nr. 170) and the "doseur" (piece Nr. 175) may remain functional for extensive periods of time as they are housing only small metallic parts and rubber/nylon seals immersed in hydrophobic LHM.
    In principle it is therefore quite unlikely to have such components become dysfunctional over time unless a part is unexpectedly breaking or a channel inside the body becomes clogged because of impurities or of LHM long ageing.
    On such components (limited) wear comes mainly from hydraulic flow, which is essentially linked with the actual use of the braking system and mileage of the car, not the case of my low mileage car that was stored for a very long time.
    Gunk from LHM sitting still for very long times could however not be dismissed.
    Do you think that a reconditioning of the CJDJ and doseur should be considered as a precautionary measure or would that be overkill?

    Same question for the LHM pump, which seems however to function correctly.

    Then the issue of hoses in the high and low pressure circuit and metal tubes in the HP circuit only.
    The HP part is the most important of course and should be 100% reliable while the LP hoses only ensure the flow back to the LHM reservoir.
    All the hoses seem to be original. Should they be all replaced or only the HP ones?
    Wrt the metal tubings, they seem to be corrosion free; should they be replaced also or could I consider that they are safe enough?
     
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  12. Nembo1777

    Nembo1777 F1 World Champ
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    Serge in Belgium you have two excellent shops which we covered in my book Classiche Masters: l'officina in Overijse near Brussels and Mistral Classics in the Flemish region. They can help you. For hydraulic parts, spheres supplies etc the go to place is Blondeau near Paris: https://www.blondeau-ds.fr/

    Now settings for the spheres are harder in Masers than in the SM but this is not my domain just make sure you get the right info from the right sources such as the experts here.

    Blondeau does echange standard for the spheres: you provide yours and they provide you freshly rebuilt ones plus a (core) fee. You speak French but for others who may be interested they can manage orders in English.
     
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  13. 71Satisfaction

    71Satisfaction Formula 3

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    Your questions are well considered.

    My general response is as follows:
    If you use your LHM Maserati regularly, most seals and components will not dry out or corrode or fail suddenly. My experience is your most common symptom will be dripping LHM, and you trace the leak to a cracked or worn seal. Then you repair the problem. Such leaks can occur at any part of the LHM system. I do not try predicting what to repair or replace before a leak occurs unless the 'Lo Pressure' light tells me.

    My specific response is;
    1.) You are correct. Parts 170 and 175 are rarely in need of any reconditioning if they are functioning normally. I have not had mine served, repaired, or reconditioned.
    2.) The LHM pump will give you trouble when it is worn out. I do not recall the symptoms, but dry, cracked or worn seals probably introduce air, and the pump will activate and work much more frequently to keep pressure (you hear the Click-CLACK-run-run-run-Click-CLACK! sound often). Mine needed reconditioning after being neglected for 22 years. That was 9,000miles ago.
    3.) My HP hoses are all original. I inspect the car each season. I do not plan on replacing them as a precaution.
    4.) Metal tubing will not corrode from the inside. If you see corrosion on the outside, it seems reasonable to replace them.

    Cheers,
    - Art
     
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  14. boralogist

    boralogist Formula Junior

    Jun 21, 2005
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    In case somebody is interested---
    Talking to my friend Maurice in NZ last night he tells me that he is now re-manufacturing our old useless Bosch rams as screw-top serviceable units. A first AFAIK.
    Regards.
     
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  15. staatsof

    staatsof Nine Time F1 World Champ
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    Well someone had been doing it for quite some time. They even advertised it as such on eBay. I always thought it was the guy you mentioned? Come to think of it that guy might have been in Australia?
     
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  16. emsiegel13

    emsiegel13 Formula Junior
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    Maurice is from New Zealand and I've dealt with him. He is a great source and makes wonderful rams. If he is back in business I want to get another ram from him for my seat.
     
  17. boralogist

    boralogist Formula Junior

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    Image Unavailable, Please Login
    FYI
     
  18. 71Satisfaction

    71Satisfaction Formula 3

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    For more extensive discussion of Maserati hydraulic repairs and parts sources, here is a separate thread devoted to the topic:
    https://www.ferrarichat.com/forum/threads/citroen-hydraulics-khamsin-bora-early-merak-late-indy.228217/page-3#post-142917976

    My understanding is it was always Maurice in NZ who designed, machined and assembled these threaded, rebuildable pistons as illustrated above. Their availability came and went depending on the stock he had fabricated and on-hand. He didn't make them on demand. Glad to see he has them available again.

    Wills Imports - is the man who rebuilds the OEM parts. You ship him your original parts and he'd rebuild, then send them back to you. He is - or was - in Salt Lake City, UT.

    On the east coast, Dave Burnham Citroen rebuilds the main accumulators and compressor pump.

    Cheers,
    - Art
     
  19. am117au

    am117au Karting

    Apr 22, 2014
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    Maurice in NZ is definitely the go to person if you need headlight rams either rebuilt or new or rebuilt switches. He owns a Bora and is fanatical about the work he does. Highly recommended
    Greg.
     
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