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Old 8th July 2018, 09:41 AM
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Styria Styria is offline
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Join Date: Feb 2008
Location: Sydney
Posts: 8,159
Default 6.9 Levelling Valves

I have rebuilt several of those valves for resale on an exchange basis. All units have been bench tested and will work well to the extent that I can provide a twelve months warranty. The 6.9s have two valves controlling the level function on each car for the front and rear respectively. So, just the two valves.

In rebuilding those valves, it is essential to understand their features and characteristics and how they function. I am in possession of the proper workshop manual, and whilst there are many items explained in full, the language used to describe functions and tests can easily lead to confusion and lack of understanding. Furthermore, the manual does not specify measurements of seals, so when one disassembles a valve, you are faced with worn components that are difficult to interpret into actual measurements required for a potential rebuild. I have also found inaccuracies in the drawings of a particular feature of the valve and, additionally, schematic drawings will not help you in determining how the system works. They are utterly confusing.

My prices are well below those charged by overseas sources located in the US and Germany, and I am ready to supply those valves on an exchange basis. I have also noticed in various advertisements on ebay that the operating lever has been turned into a position where they can damage the internal operation of the valve. Any such valve should be treated with suspicion. Regarding efficiency of Air Cells also known as footballs etc. The preferred method of screwdriver insertion as a means of determining a unit's effectiveness is just about totally useless unless a cell is completely collapsed, and you don't need a screwdriver to illustrate that. If a cell even has remaining pressure of less than half, there is no way that a screwdriver will force the membrane further into the unit. Mercedes recommends minimum pressures for both the front and rear units and those minimums can only be ascertained with the appropriate measuring equipment.

All other components of the system can also be assessed and tested for efficiency, such as the pressure oil pump, Pressure Regulator as well as the check valve that is attached to the Regulator. Regards Styria
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