Best way to Bleed the Brakes? RHD CSI

Discussion in 'E9 General Discussion' started by Cornishman, Jun 15, 2014.

  1. Cornishman

    Cornishman Member Site Donor

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    I have researched the forum for the best way to bleed the brake system, there is a little conflicting information and no definitive answer, perhaps it is an art and not a science. Also I have a Right Hand Drive so remote master to the servos.
    Here is what I did after a rear axle rebuild and change to stainless flex hoses, hence the system was near empty of fluid.
    Dot 4 fluid and a pressure bleeder attached to my bike tyre, so don't know the actual pressure.
    1 rear left and right calipers. Bleed nipple is at the top of the caliper.
    2 Front left, lower inside nipple, then outer lower nipple, then upper. The manual does not say if lower before upper, but says outer before inner bleed nipples.
    3 Front right, as for left.
    This gave no pedal resistance.
    4 Bled both servos, which gave some air.
    Now I have a reasonable pedal resistance, but not perfect.
    Repeat all of above again.
    Very little air came out this time and what did was in tiny bubbles, like quality champagne!
    Pedal movement and resistance pretty good but not perfect, I can’t tell the difference between rubber flex hoses and these steel ones, so suspect a little air still in the system.
    Is there a better way to the job than this?
    However, she is now back on the road after the rear end rebuild, so here is a before and afterwards shot for your amusement.
    Best wishes
    C
     

    Attached Files:

  2. deQuincey

    deQuincey Well-Known Member

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    hi c.
    i use a vacuum system from HAZET, it uses the compressor air to create vacuum through a venturi effect
    i assume this makes no difference,
    first i bleed the clutch, then the calipers
    i start by the front left, then front right then rear left, and rear right, then repeat all again once more
    the sequence of the fronts is defined in the book, A, B, and then C
    it helps to change liquid colour, ATE has yellow and blue for the DOT4, yeah you are not in the US, so you can still use BLUE like me !:mrgreen:
     
  3. sfdon

    sfdon Well-Known Member

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    Fog light?

    Is that a fog light at the right rear?

    Those empty dry lines are a real problem. You end up with thousands of tiny bubbles.

    Your first lack of success was caused by air in the master.

    Now you have decent but not great brakes. Drive the car for a week and re bleed.
    You should get the last air out then.
     
  4. Cornishman

    Cornishman Member Site Donor

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    Don
    Yes, it is a fog light. I never considered that is may be other than standard.

    Thanks for the advice, I will do as you say and leave it for a week or so.
    Regards
    C
     
  5. Stevehose

    Stevehose Well-Known Member Site Donor

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    I've had success gravity bleeding to start off the process, this fillus up the passages without creating bubbles. Open up all the bleed screws and let the fluid drip out for a few hours, topping off as necessary, then close them and bleed as normal, starting with the caliper farthest from the master cylinder.
     
  6. Ian C

    Ian C Member

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    I believe the servos should be bled first, then rear then front
     
  7. kasbatts

    kasbatts Member Site Donor

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    I agree with Ian here.

    I bleed the 2 x remote masters first to get as much air out as possible ( I also had the nose of the car slightly pointing up for this to help get air to travel along to the bleed screws at the end of the cylinders)
    Then the Left rear, Right rear, Left front, Right front.

    I made my own pressure bleeder using a pump up garden sprayer, worked a treat, much much easier than trying to pump through with peddle.
     
    Last edited: Jun 16, 2014
  8. bill

    bill Member

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    In my experience, you bleed the calipers as per all the instructions which you have seemed to have followed well enough. The last step is to bleed the master and you do that by loosening the pipe to the rear brakes at the master then having faithful/patient wifey (or whomever) push down the pedal and letting fluid squirt out, then tighten the connection, release the pedal.Then you do one of the front circuits ( probably the one farthest away from the master IIRC) then you do the other circuit. It's a little messy, but it has to be done to get all the air out. Then treat yourself and wifey to a couple of Fuller ESBs. This method has worked for me.
     
  9. roundel

    roundel Member

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    Brake belleding....

    When I worked for BMW back in the 1970`s we had constant problems with RHD brakes. But the system we always found worked best was this....
    front servo
    NSF upper
    OSF upper
    rear servo
    NSR
    OSR
    NSF inner
    NSF outer
    OSF inner
    OSF outer

    If you still have a long pedal it is sometimes helpful to push all of the calliper pistons right back in as far as they will go all at the same time. This has the effect of pushing any small air bubbles back up to the reservoir.
    Alex
     
  10. Simufly

    Simufly Active Member

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    Bleeding brakes .

    When you say front and rear servos, which is the upper and which the lower?
     
  11. GRKOALA

    GRKOALA Peter K Site Donor

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    Is there any update on bleeding the difficult Right Hand Drive brake system? Is there any new technology to remove the last bit of air in the system? I’ve bled the brakes 3 times and they have improved every time but They are still not up to standard
     
  12. Cornishman

    Cornishman Member Site Donor

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    SFDons advice seemed to work, bleed them and then drive it, then do again. Tjis is to shake out the small bubbles.
    However, despite what a few people say, I feel that RHD brakes just do not work that well and are simply not comparable to a modern car.
    I met someone who had put the servos from a 635 into an E9, he said that they are slightly larger and that this made them slightly better. He took me out to demonstrate this and yes they were better, but I would have liked even better still.
     
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  13. Rek

    Rek Active Member

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    I am looking at single circuit E32 brakes now on the advice of a member. I am hoping that they just bolt on, after the calipers have been renovated. My brakes are fine but not up to modern standards. It would give me a lot more confort if they were.

    Does anyone have experience of using these?
     
  14. Drew20

    Drew20 Active Member

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    What I've done before is cycle the same fluid through several times and, once the pedal is firm, swap this re-cycled fluid for new
    So buy 2 litres, use the first litre to do the initial flush or fill, and then re-use it as often as necessary, over a period of days if need be (I've not tried driving the car to shake small bubbles into big bubbles, but makes sense), to get all the air out
    Once you've got a good pedal, and no more champagne, put the second litre of fluid in to replace the much flushed fluid
    Helps to not be in a hurry!
     
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  15. roundel

    roundel Member

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    The front is just that, the one nearest the front of the car that does the front brakes.......it is also helpful to use a pressure bleeder......
     

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