Discussion in 'Wheels, Tyres, Brakes & Suspension' started by MicB, Apr 13, 2017.

  1. MicB

    MicB Hardcore MB Enthusiast

    Nov 2, 2010
    Beckley, Oxford
    MB SL500 (R230) 2003, MB SLK320 (R170) 2001, Volvo V70 XC AWD 2001
    On Sunday evening my car displayed, in white, ABC visit workshop

    On Monday morning on start up the car displayed, ABC drive carefully (superfluous advise as I always drive carefully ***!!!???)

    Some ABC fluid on my garage floor but on checking there was enough fluid in the reservoir (I hoped) for me to drive the thirty miles to Star Motor Service; which I did without incident albeit with the bouncy castle symptom.

    The car is 13.5 years old and has covered 135k miles. ABC pumps have possibly got an average life expectancy of 60k-80k miles; pulsation dampers and accumulators a possible life expectancy of circa 10 years.

    My car had a replacement pulsation damper (used because there happened to be one in the workshop) when it was twelve years old so the first job was to replace the used pulsation damper with a new pulsation damper. If the pulsation damper has worn out (failed) then it is highly probable that the two (front and rear axle) accumulators are also near the end of their serviceable life so these were replaced with new ones as a piece of preventative maintenance and of course to eliminate the accumulators as being the culprit of the ABC fault.

    I will not bore you with how the diagnostics went from this point onwards, partly because I am not entirely clear myself but mostly because you would likely lose the will to live if I record all the diagnostic procedures (If you really need to know ask Ian).

    In summary the pump would hold pressure at a steady 185 bar once “primed” by revving the car but not from cold on tick over and/or would not recover/build pressure from low pressure so the conclusion was that the suction valve was fine but the pump had failed. The suction valve is not available as a separate item from the pump…….happily I still had the car’s original pump c/w suction valve stowed away in my garage from when it was replaced (at 60k miles when the car was 7 years old) because the suction valve part had failed.

    So the original pump part from my garage (60k miles old) was married to the suction valve part just taken off the car (75k miles old) and then fitted to the car…….sound diagnosis…….because all is well with my car for the time being at least.

    The future life of this combination is of course unknown other than it is certain to be less than a whole new replacement combination at circa £600. If I get a couple of years then a good result…….if I only get a couple of months then not so good.

    A big thank you to Ian and his team for working through this one.......well done chaps.

    1 person likes this.

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