moretech

I'm not totally sure yet but I may be developing a very small leak or a bit of seepage in the line that attaches to the pulsation dampener assembly in the rear of the front wheel well. This one has the banjo fitting secured by a large nut to the side of the pulsation dampener assembly. This is a short section which has another coupling just below the wheel well. Can anyone tell me it's #? Is this a high or low pressure line? I do not see any drips or fluid loss but I am watching it carefully to see if residue returns. I have cleaned it thoroughly. Thanks for any info.
moretech

kbob999

Pretty sure this is a high pressure line direct from the pump. And since it is upstream of the pulse dampener, likely has the highest line pressures.
Mine started 'sweating' recently, which means it has pinhole leaks somewhere. I'm monitoring it, but if it gets worse, or blows, I'll replace it. Don't know the part number.

moretech

Thanks kbob! I sort of thought after really looking this over it may well be from the pump! It may have been leaking a long time but residue is rather dry rather than oily and fluid level has always been to the mark, so I will watch very carefully. What I really wonder is if I must pull the line out will the pump drain totally making a restart of the system more of a problem as far as air getting in the system.


moretech

kbob999

I'd just keep an eye on it to see if it starts weeping again. Could be residual from a prior issue.

If you do drain your pump, and the system sees zero pressure, it locks down the ABC struts and throws the red warning, which can't be cleared without an SDS. Ask me how I know.
So if you do replace the pump or lines I'd recommend priming the pump and lines with fluid before starting.

You can also apply 10 psi air to the ABC reservoir with an air nozzle to prime the pump at startup. This forces fluid in during the 1st few seconds when the ABC system does not read pressure. I was told this was to prevent ABC warnings during startup when pressures are low. After a few seconds it reads pressure, and if low, locks it down. This is what the tech did that brought my car out of lockdown.

Rudeney

The main pressure line from the pump connects to the front axle valve unit (Y36/1), which sits ahead of the front left wheel. I just replaced this hose on mine as it had a pinhole in the first rubber section right in front of the pump. If you look at the diagrams (see below), it shows this hose connecting directly to the pressure supply valve (behind the front left wheel). I suspect that the connection to the front axle valve is just a "pass-through" on its way to the pressure supply valve (52), which means there is another line from Y36/1 to 52:

http://benzbits.com/R230/ABCElectricalComponents.pdf
http://benzbits.com/R230/ABCHydraulicComponents.pdf
http://benzbits.com/R230/ABCHydraulicDiagram.pdf