[Oxygen]

A few months back a member from this board came to our shop ( TTMotorsports / http://www.mbworld.org/forums/member...torsports.html ) with a 2003 CL600 that had a serious problem with the front end sinking after being turned off for a few minutes.

The car also make a crazy crunching/cracking/dinging sound coming from the ABC pump and would not rodeo for more than a few minutes because the pump would not produce enough pressure.

Our first attempt to remedy the problem was to filter the ABC fluid but that had no effect and the car would sink to the ground after being off for about 3 minutes.

The front axle valve block was obviously malfunctioning and needs to be replaced along with the pump and the leaky high pressure expansion hose.










One of the first things you must do is suction off the hydraulic fluid in the ABC and PS tanks...




The front axle ABC valve clock hiding behind a maze of hydraulic hoses...



Front driver's side wheel well needs to be removed to provide access to the front axle valve block and the pressure accumulator...



The black bulb is the front axle pressure accumulator and it is on the same plate as the front axel valve block. The whole assembly is removed once the hydraulic hoses are disconnected from the valve block...



Here is what 7 years of improvement look like... the valve blocks are not manufactured by the same company...






Here is the new valve block assembled with the mounting plate and the pressure accumulator.

The valve block has 4 electrical connections and 5 hydraulic connections.. they are as follows:

SP: Pressure Accumulator
S: High Pressure Feed
T: Low Pressure Return
FB1: Front Left Strut
FB2 Front Right Strut







The new valve block installed and all hydraulic and electrical connections are assembled:



When I initially diagnosed the car I noticed that the high pressure expansion hose that connects to the pump was sweating a lot of hydraulic fluid on the surface and would eventually fail, causing the same failure that happened to my S600 months back. With the new pump working correctly I did not want to subject the old hose to the high pressure and it needed to be replaced.

Here's a comparison between the old and the new hoses...






Installation of the hose is a bit tricky.. the motor mount needs to be unbolted from the subframe and the motor needs to be raised a few inches since the hose runs underneath the crank pulley and the subframe...









Here is the new and the old pump. The older pumps were manufactured by LuK but they were since bought and are now manufactured by a company called Ixetic. Exterior case is exactly the same. The suction restrictor valve looks to be updated..




New pump installed and awaiting feed lines to be connected..